NBER WORKING PAPER SERIES
TIME-TO-PLAN LAGS FOR COMMERCIAL CONSTRUCTION PROJECTS
Jonathan N. Millar
Stephen D. Oliner
Daniel E. Sichel
Working Paper 19408
http://www.nber.org/papers/w19408
NATIONAL BUREAU OF ECONOMIC RESEARCH
1050 Massachusetts Avenue
Cambridge, MA 02138
September 2013
The views expressed in this paper are ours alone and are not necessarily those of the Board of Governors
of the Federal Reserve System, its staff, any other institutions with which we are affiliated, or the National
Bureau of Economic Research.
NBER working papers are circulated for discussion and comment purposes. They have not been peer-
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© 2013 by Jonathan N. Millar, Stephen D. Oliner, and Daniel E. Sichel. All rights reserved. Short
sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided
that full credit, including © notice, is given to the source.
Time-To-Plan Lags for Commercial Construction Projects
Jonathan N. Millar, Stephen D. Oliner, and Daniel E. Sichel
NBER Working Paper No. 19408
September 2013
JEL No. E22,E32,L50,L74,R52
ABSTRACT
We use a large project-level dataset to estimate the length of the planning period for commercial
construction projects in the United States. We find that these time-to-plan lags are long, averaging
about 17 months when we aggregate the projects without regard to size and more than 28 months
when we weight the projects by their construction cost. The full distribution of time-to-plan lags
is very wide, and we relate this variation to the characteristics of the project and its location. In
addition,we show that time-to-plan lags lengthened by 3 to 4 months, on average, over our sample
period (1999 to 2010). Regulatory factors are associated with the variation in planning lags across
locations, and we present anecdotal evidence that links at least some of the lengthening over time to
heightened regulatory scrutiny.
Jonathan N. Millar
Federal Reserve Board
20th and C Streets, NW
Washington, DC 20551
Stephen D. Oliner
American Enterprise Institute
1150 17th S., NW
Washington, DC 20036
and UCLA Ziman Center for Real Estate
Daniel E. Sichel
Department of Economics
Wellesley College
106 Central Street
Wellesley, MA 02481
and NBER
- 1 -
I. INTRODUCTION
The U.S. economy emerged from recession in mid-2009, but commercial construction
activity did not hit bottom until nearly two years later and even now is up only slightly from its
low. Although the recent weakness partly reflects the tight credit conditions induced by the
global financial crisis, commercial construction also lagged behind the broader recovery in each
of the three previous business cycles. Averaging across those recoveries, which date back to
1982, commercial construction reached its low about three quarters after the official business
cycle trough determined by the National Bureau of Economic Research.
1
The cyclical dynamics
of commercial construction matter for the macroeconomy because activity in this sector is quite
volatile and contributes significantly to economic downturns.
2
A plausible explanation for why commercial construction lags the business cycle is that
these buildings require substantial planning before construction can begin, which delays the
upturn in this sector. This explanation resonates with the use of gestation lags in some
macroeconomic models, starting with Kydland and Prescott (1982). Two distinct types of
gestation lags can be defined. The time-to-plan lag of a project represents the time elapsed
between the initiation of planning and the start of construction, while its time-to-build lag
represents the period from the start of construction until completion.
Although time-to-build lags have garnered most of the attention in the literature, time-to-
plan lags are also important for understanding how economic fundamentals affect construction
1
This calculation is based on data in the National Income and Product Accounts for real investment in commercial
and health care structures.
2
From 1959:Q1 to 2012:Q4, the standard deviation of quarterly percent changes in real investment in commercial
and health care structures was about five times that of real GDP. And, around the time of recessions, this sector
typically makes a negative contribution to aggregate activity that far outstrips its small share of nominal GDP (1.2
percent on average from 1959:Q1 to 2012:Q4). For example, in the latest recession, which began at the end of 2007,
real GDP dropped 4.7 percent, and the associated decline in real investment in commercial and health care structures
reduced real GDP by about 0.5 percentage point. In each of the prior two recessions, which began in 1990 and
2001, the drop in this category amounted to an even larger share of the decline in real GDP.
- 2 -
and other types of investment activity. In particular, the decision to undertake a construction
project will reflect information available during the planning period, including current and
expected economic conditions as well as a host of regulatory and other factors specific to the
locale of the project. Once construction has started, it typically becomes very costly to defer or
abandon the project if circumstances change.
3
Thus, the planning period is the critical window
for the formation of expectations and the perceptions of risk that drive construction spending.
Existing empirical work, however, provides very limited information about time-to-plan
lags for investment projects. One strand of this literature incorporates gestation lags into the
structure of a model and estimates the lags in conjunction with other parameters.
4
These studies
generally point to time-to-build lags of one to two years for structures or broader aggregates of
capital spending but are largely silent about the length of time-to-plan lags.
5
The second strand
of the literature directly measures gestation lags. To our knowledge, only one study, Mayer
(1960), provides direct measures of the time-to-plan lag. Using survey data on new industrial
plants and additions to existing plants, he estimated a mean time-to-plan period of 7 months and
a mean time-to-build period of 15 months. Other studies (Krainer 1968; Taylor 1982;
Montgomery 1995; and Koeva 2000) measure either the time-to-build lag or a combination of
that lag and part of the time-to-plan lag; these lags are estimated to be long ― about 1½ years or
more. None of these studies, however, separately identifies the planning period.
3
For a discussion of investment under uncertainty and the role of irreversibility, see Dixit and Pyndyck (1994). For
applications to commercial real estate, see Holland, Ott, and Riddiough (2000) and Sivitanidou and Sivitanides
(2000).
4
For estimates of gestation lags from investment models, see Oliner, Rudebusch, and Sichel (1995), Zhou (2000),
Koeva (2001), Millar (2005a), and Del Boca et al. (2008); for estimates from dynamic factor demand models, see
Palm, Peeters, and Pfann (1993) and Peeters (1998); and for estimates from business cycle models, see Altug (1989)
and Christiano and Vigfusson (2003). Other business cycle modelsincluding Kydland and Prescott (1982),
Christiano and Todd (1996), Casares (2006), and Edge (2007)have incorporated gestation lags that were
calibrated using information outside the model.
5
One exception is Millar (2005b), who found that it takes at least one year for shocks to total factor productivity to
induce changes in spending on business fixed capital, a lag that was interpreted as the time-to-plan lag.
- 3 -
This paper begins to fill that void by providing comprehensive estimates of time-to-plan
lags for commercial construction projects and by exploring the sources of variation in these lags.
We estimate time-to-plan lags using a large project-level dataset from CBRE Economic
Advisors/Dodge Pipeline, a commercial vendor of real estate data, supplemented with
information about the project's locality from the Census Bureau and other governmental sources.
The dataset covers more than 80,000 commercial construction projects in the United States from
1999 to 2010. Our goal is to present new stylized facts about time-to-plan lags from a rich and
previously untapped dataset. We do not estimate structural models that could be used to identify
causal relationships. As valuable as that would be, it is beyond the scope of this paper.
Our analysis generates four main results. First, time-to-plan lags are quite lengthy for
commercial construction projects, averaging about 17 months across the projects in our dataset.
Large projects — which account for a disproportionate share of total construction spending —
tend to have even longer lags. Indeed, when we weight the projects by their construction cost,
we find that the average time-to-plan lag associated with a given dollar of commercial
construction spending is more than 28 months. Second, time-to-plan lags vary considerably
around these averages depending on the characteristics of the building and its location. For
example, as would be expected, time-to-plan lags are longer for larger, more complex projects;
we also find that the metropolitan statistical areas (MSAs) with the longest time-to-plan lags are
concentrated in California and the Northeast corridor. Third, time-to-plan lags lengthened
significantly from 1999 to 2010, rising by an average of 3 to 4 months. This increase was
widespread, occurring for all types of buildings, in MSAs across the population spectrum, and in
most regions of the country. Finally, we find that the variation in planning lags across locations
is associated with differences in land-use regulation, and we present anecdotal evidence that
- 4 -
links at least some of the lengthening in planning lags over time to heightened regulatory
scrutiny.
6
The rest of the paper is organized as follows. Section II describes our data, and section
III presents the regression analysis. Section IV focuses on whether differences in land-use
regulation can account for the variation we find in planning lags across MSAs and over time.
Section V concludes.
II. DATA
We assembled our dataset using project-level data from the CBRE Economic
Advisors/Dodge Pipeline database, supplemented with information about localities from the
Census Bureau and other governmental sources. The Pipeline database includes more than
250,000 commercial construction projects planned in the United States from 1999 to 2010.
Pipeline aims to include all office, hotel, retail, and warehouse projects started since 1999 with
estimated construction costs — excluding land and design fees — that exceed $500,000 at the
time of the start.
7
Pipeline also includes projects meeting these criteria that have been planned
since 1999 but have not yet been started because they were abandoned, deferred, or are still in
the planning process. After accounting for missing data and other exclusions, our regression
sample consists of 82,303 projects — about 85 percent of which (69,723) were started before our
cutoff date of December 2010.
The key information in Pipeline for this study is that on project timelines. After field
representatives identify a potential new construction project, they track the dates at which the
6
We are not aware of other research on the effects of land-use regulation on the commercial real estate sector. On
the residential side, recent papers that have examined the effects of land-use regulations on housing supply and
home prices include Mayer and Somerville (2000), Ihlenfeldt (2007), Saks (2008), Glaeser and Ward (2009), Saiz
(2010), and Huang and Tang (2012). For reviews of this literature, see Quigley and Rosenthal (2005) and Gyourko
(2009).
7
This cost threshold is not a hard lower bound, as nearly 5 percent of the projects in our sample had nominal
construction costs below $500,000.
- 5 -
project transitions through its planning process. The planning timeline begins with the
preplanning phase, when the developer has announced an intention to build but has not yet hired
an architect, then transitions to the planning phase, when architects are hired to draw up
schematics for the building, and to the final planning phase, when specific plans have been (or
are about to be) finalized.
8
During these three phases, the developer also completes the many
legal steps (such as holding public hearings and obtaining zoning approvals from local
governments) needed to secure regulatory approval for the project. Once the planning phases are
completed, Pipeline representatives record when construction on the project started. If the
developer decides to defer the project or abandon it altogether at any time before completion,
these dates are recorded as well.
9
The Pipeline database shows the exact month and year during which construction on the
project began, but the other dates on the project timeline are recorded with less precision. These
other dates are less precise because the Pipeline field representatives are only required to check
on each project once every six months during the planning period. Thus, the dates recorded for
the beginning of each phase prior to the start represent the month and year during which the
representative discovered the change of status, rather than the actual date of the change. For this
reason, the reported dates for all changes in status before the start represent the end of a six-
month interval in which the actual change occurred.
10
We account explicitly for this interval
reporting in our empirical work.
8
In addition to these phases, Pipeline also documents when bids were solicited from general contractors, when a
contractor was hired, when construction permits were obtained, and when the project was completed.
9
Although a project could, in principle, be deferred or abandoned multiple times before completion, only the first
instance of each of these events is recorded in Pipeline.
10
In some cases, the interval containing the status change can be narrowed further by the constraint that planning
cannot occur after the measured start date. For instance, if a measured planning date is three months after the listed
start date, the actual planning date must have occurred within the three-month interval preceding the start, and so on.
- 6 -
For our analysis, we define the time-to-plan lag for started projects as the number of
months between the beginning of the planning phase, subject to the interval reporting issue just
noted, and the date of the construction start. The decision to exclude the earlier preplanning
phase was dictated largely by data availability. Dates for the preplanning phase were available
only for the small fraction of projects that could be identified at their inception through industry
contacts.
11
These projects tended to be much larger and more costly than the median project in
the dataset. All told, we were able to determine the beginning of the planning phase for nearly
90,000 projects that were started prior our cutoff in December 2010, compared to only about
12,000 projects based on the earlier preplanning date.
12
Many of the projects in Pipeline had not yet been started by our cutoff date of December
2010. Excluding such records would cause our sample to underrepresent projects with longer
planning durations, thereby exposing our results to truncation bias. To address this issue, we
employ an estimation method that regards the time to plan for unstarted projects as being right-
censored, with a true planning duration at least as long as the number of months between the
planning date and the cutoff date. Although this approach deals with the potential for truncation
bias, it can introduce a separate bias in the opposite direction. In particular, some unstarted
projects may be very unlikely to move forward, yet remain in the Pipeline database because the
developer has not formally declared the project abandoned. To deal with these potential
"zombie" projects, we exclude from our sample any unstarted projects whose status at the
December 2010 cutoff date had been listed as deferred for more than 60 consecutive months.
11
Field representatives attempt to identify projects as early as possible by canvassing neighborhoods, exploiting
information from industry contacts (such as developers, architects, and contractors), and as a last resort
through information from local permit offices.
12
We observe both the planning and preplanning dates for about 5500 projects that were started before December
2010. The beginning of the preplanning phase for this limited set of projects was about 8 months earlier, on
average, than the beginning of the planning phase, while the median difference between the two dates was 5 months.
- 7 -
We also excluded any projects that were listed as abandoned prior to the cutoff date, as
abandoned projects very rarely are resumed at a later date.
13
To account for the effects of project-specific factors on time-to-plan lags, we assembled
data on a number of project characteristics. From the Pipeline database, we obtained the location
of each project (including its MSA, county, and geocode), building type (office, hotel, retail, or
warehouse), construction type (new buildings or additions, alterations, or conversions of existing
structures), number of buildings, total number of floors, square footage, and dummy variables
indicating whether the project had been deferred prior to groundbreaking. For each project, we
calculated distance to the city center using geocodes for the project’s location and the
employment-weighted center (from the Department of Housing and Urban Development).
14
We
also obtained Pipeline data for each project’s construction costs in current dollars, which were
converted to real terms using the price deflator for nonresidential buildings from the National
Income and Product Accounts that prevailed at the planning date.
These project-specific variables were supplemented with MSA- and county-level controls
from the 2000 Decennial Census. Specifically, we use MSA-level estimates of population, and
county-level estimates of the average number of persons per household, the urban share of the
population, the homeownership rate for occupied housing units, the median house price, median
household income, and the share of the households who had high income (annual income above
$100,000). These characteristics could influence land-use regulations across localities and
thereby cause planning durations to differ across projects that are identical except for the
jurisdictions in which they are located.
13
We used information from outside sources (such as company reports) to verify whether some exceptionally large
deferred projects in Pipeline actually had been abandoned. This search eliminated one $5 billion project from our
sample that would not have been excluded by other criteria.
14
In a handful of instances for which geocodes for the MSA city center were unavailable from HUD, we used the
location of city hall from Google Maps as the city center.
- 8 -
Table 1 reports the distribution of projects along several dimensions. As shown in the top
part of the table, most of the projects in our sample had their primary property type listed as
office or retail, with the remainder split between warehouse and hotel properties.
15
About
95 percent of the projects were for new buildings, with the remainder involving some
combination of additions to existing buildings, alterations that do not affect square footage, or
conversions of property type (such as transforming retail space to office). Geographically, the
South Atlantic division, which stretches from Maryland to Florida, accounts for more than
20 percent of the projects, while New England contains about 5 percent, reflecting its much
smaller population. The shares for the other divisions are all between 10 and 20 percent. About
90 percent of the projects were located in MSAs in the top population quartile; the 25 most
populous MSAs alone contain nearly 40 percent of the observations in the dataset and account
for roughly half of total construction cost.
As shown in table 2, the projects in our sample vary substantially by size, cost, proximity
to city center, and characteristics of the surrounding county. Although the typical project in our
sample involved the construction of a modest one-story building, the indicators of project size
(number of buildings, number of floors, and construction cost) have pronounced right tails that
push the mean values above the medians. In the location dimension, projects range from being
nearly at the city center to more than 65 miles away. As can be seen in the lower panel of the
table, the projects are located in counties with widely varying characteristics. The counties in the
dataset tend to be somewhat more urban and to have higher housing density than the overall
mean in the 2000 Census. However, the mean values for all the other county characteristics are
similar to the national averages in that year.
15
The shares of construction cost are roughly consistent with those implied by Census Bureau estimates of
aggregate nominal construction spending for these categories over the same period.
- 9 -
III. REGRESSION ANALYSIS
We use the project-level dataset described above to estimate how our control variables
affect time-to-plan lags and to characterize the distribution of these lags. To estimate the
regression, we employ a maximum likelihood procedure that accounts for both the interval
reporting of the initial planning date and the right-censoring of the measured planning duration
for unstarted projects, under the assumption that the true residuals are distributed normally.
16
A. Explanatory Variables
The explanatory variables for the regression consist of characteristics of the project itself,
characteristics of the county in which the project is located, and time and MSA fixed effects.
17
The project and county characteristics include all those shown in table 2; for each variable, the
regression contains both linear and quadratic terms to allow for nonlinear effects. We also
include dummy variables for the type of building (retail, warehouse, or hotel properties, with
office buildings as the omitted category); type of construction (additions, alterations, or
conversions, with new construction as the omitted category); and whether the project was ever
deferred. We interact the deferral dummy with both linear and quadratic terms for the project's
square footage to allow for the possibility that deferrals lengthen the planning period by differing
amounts for small and large projects.
16
We use the intreg routine in Stata. The Pipeline database includes many projects that we omitted from the
regression sample because of missing information for some variables, which raises the possibility of sample
selection bias. Although the intreg routine does not accommodate the usual Heckman two-stage procedure to assess
sample selection, we implemented the Heckman estimation in an OLS framework. We found both that the inverse
Mills ratio was insignificant and that the coefficient estimates were quite similar to the OLS estimates without the
Heckman correction. In light of these results, we did not pursue sample selection issues further. The results from
the Heckman estimation are available from the authors on request.
17
Variations in economic uncertaintyboth over time and across MSAsalso could help to explain variation in
time-to-plan lags. In particular, greater uncertainty could lead to the deferral of a project start, thereby extending the
planning period. The role of uncertainty, however, extends beyond the scope of this paper; in research in progress,
we use hazard models to investigate the effect of uncertainty and other factors on the decision to break ground on a
commercial construction project.
- 10 -
The remaining variables in the regression are time and MSA fixed effects. We include a
year fixed effect for the year in which project planning began (with 2004 as the omitted year)
and a month fixed effect for the same event (with June as the omitted month). The regression
also includes 362 MSA fixed effects (with Atlanta as the omitted MSA). One of the 362 fixed
effects covers about 4900 projects located in MSAs with a population of less than 50,000 in the
2000 Census or for which the MSA could not be determined using location fields in Pipeline.
18
For ease of interpretation, we specify our regression so that the constant term represents
the planning lag for a baseline project. This baseline project is defined from the omitted
categories for the dummy variables, the omitted fixed effects, median characteristics of projects
in our sample, and county characteristics for Fulton County, Georgia (which contains the center
of Atlanta, the omitted MSA). The constant captures median project characteristics because we
normalize every non-dummy project variable (except distance to city center) prior to estimation
by subtracting its median across all projects in the sample; similarly, we normalize every county
characteristic by subtracting the value for Fulton County. With these conventions, the constant
represents the fitted planning lag for a new office project with median characteristics, located in
a city center with observed county characteristics akin to those of central Atlanta, for which
planning began in June 2004 and proceeded without deferral or abandonment.
B. Baseline Planning Lag and Effects of Characteristics
Table 3 presents the estimates, along with bootstrap standard errors, of the constant term
and the coefficients for all of the project and county characteristics. To begin, the constant term
indicates that the baseline project has a planning period of 16¼ months; this baseline planning
lag is estimated fairly precisely, with a 95 percent confidence band that runs from about
18
Note that we omitted dummy variables for the Census divisions and the MSA population groups shown in table 1.
Both of these sets of dummy variables are perfectly collinear with the set of individual MSA dummies and thus
cannot be identified separately from the MSA fixed effects.
- 11 -
15 months to 17½ months. This result confirms that the planning lags for a typical commercial
construction project is lengthy. The differences in the estimated planning lags for the various
types of buildings and types of construction are relatively small, though some of the differences
from the baseline are statistically significant. Among the significant results, the planning lags for
retail buildings and hotels are roughly one-half to a full month longer than for office buildings,
while the planning lag for additions to existing structures is a bit more than one month shorter
than for new construction.
Moving to the next block of the table, the dummy variable for project deferral has an
enormous effect on total planning time. Deferral adds about 25 months to the planning lag for a
project with median square footage.
19
The effect of deferral rises to about 29 months for the
largest projects in the dataset, those at the 99th percentile of the distribution of square footage.
Accordingly, projects that were ever deferred impart a long right-hand tail to the distribution of
planning lags for the full sample.
The variables measuring project size and complexity –– the number of buildings, number
of floors, square footage, and cost per square foot — all have positive and significant coefficients
on the linear terms, combined with negative and mostly insignificant coefficients on the
quadratic terms. One county characteristic, the median home price, has the same pattern, with
significant coefficients on both the linear and quadratic terms. However, the coefficients on all
the other project and county characteristics are insignificant.
To assess the quantitative implications of these results, table 4 uses the linear and
quadratic coefficients to calculate the change in the time-to-plan lag as each project or county
characteristic increases from the 1
st
percentile value of its distribution to the 99
th
percentile value.
19
This effect is shown by the first deferral coefficient in the table because the square footage variable is defined as
the deviation from the median.
- 12 -
The table also shows the 95 percent confidence interval for the effect of the change in each
variable.
Starting with the project characteristics, increasing the number of buildings in the project
from the 1
st
to the 99
th
percentile value lengthens the planning period by 6.5 months, all else
equal, with a 95 percent confidence band that runs from 5 months to 8 months. A parallel
change in the number of floors adds 7.2 months to the planning lag, with a slightly narrower
confidence band than for the number of buildings. Boosting the total square footage of a project
with a fixed number of floors and buildings also lengthens the planning period but by less than
those two variables. Thus, as would be expected, large projects take substantially longer to plan
than small projects. In contrast, a higher cost per square foot has only a small effect on time to
plan in the presence of our other regression controls, while the effect of distance from the city
center is negligible.
Among the county characteristics, median home price strongly affects planning times.
Moving from the 1
st
percentile to the 99
th
percentile of the home price distribution lengthens the
planning period by nearly 10 months, all else equal, with a 95 percent confidence band that runs
from about 6 months to 13½ months. This result is consistent with the notion that development
plans receive heightened scrutiny when county homeowners have a lot at stake through the value
of their homes.
20
The only other county characteristic with a substantial effect on the planning
period is median income. Surprisingly, counties with the highest median income have
considerably shorter planning lags than counties at the low end of the income distribution. The
effects of all the other county characteristics — housing density, the urban share of population,
the homeowner share, and the high-income share are both small and statistically insignificant.
20
See Fischel (2001) and Saiz (2010).
- 13 -
We would caution, however, against interpreting the effects of these county
characteristics too strictly. First, even though our regression sample is large, the amount of
information used to estimate these effects is much more limited than for the project
characteristics. Our dataset contains 1593 counties, compared with roughly 82,000 projects.
Moreover, because our regression controls for MSA fixed effects and because the county
characteristics do not vary across time, the county effects are identified solely by cross-sectional
variations within the 362 MSAs in our sample. Second, the county characteristics could well be
endogenous. In particular, the factors influencing the development process in a county likely
affect both the length of the planning period and most, if not all, of the county characteristics in
our regression. To address this potential endogeneity, we estimated an IV version of our
regression with instruments for the county characteristics that included indicators of geographic
constraints on buildable land in the spirit of Saiz (2010) and demographic characteristics — such
as the age distribution of county residents — that should be much less affected by the regulatory
environment. Although the instruments pass standard specification tests, some of the estimated
county effects seemed implausible.
21
All in all, we would regard the county characteristics as
useful controls in the regression but would not attach a strong causal interpretation to the specific
results.
C. Variation in Planning Lags Across MSAs and Over Time
The "heat map" in figure 1 displays the estimated planning duration for the 362 MSAs in
our sample for a project with the baseline set of characteristics. For each MSA, the planning
21
For example, the IV results imply that moving from the 1st percentile to the 99th percentile of the home price
distribution would lengthen the time-to-plan period by roughly 40 months, four times the effect reported in table 4.
In addition, median household income no longer had a significant effect on the planning lag, and the effect of the
high-income share became negative and strongly significant. It is difficult to explain why counties with a large
share of high-income residents would have substantially shorter planning lags than an otherwise identical county
with relatively few such residents. Additional information about the IV regression is available from the authors on
request.
- 14 -
duration equals the sum of the regression constant plus the coefficient on the MSA dummy.
MSAs with longer planning times are represented by deeper shades of red. As shown, the MSAs
with the longest planning times are concentrated in California and the Northeast corridor, while
planning times generally are shorter in the interior of the country. We explore possible sources
of this variation in section IV below.
Table 5 presents results for the month and year effects in the regression. Looking first at
the monthly patterns, planning periods tend to be slightly longer — by about one-half to a full
month — when the planning starts late in the year rather than in June, the omitted month. The
reason for this minor seasonal pattern is not clear, though perhaps project planning gets a slow
start when it begins shortly before the year-end holidays.
The year effects are much more pronounced. Planning lags have increased over time,
with projects initiated in 2010 having planning periods that were roughly 3 months longer than
projects undertaken in 1999, the first year of our sample. If we measure the change instead from
2000, the year with the smallest estimated year effect, the increase in planning lags through 2010
was about 4 months. An F-test overwhelmingly rejects the null hypothesis that the year fixed
effects are equal in all years.
22
An important question is whether the upward trend is pervasive or is concentrated in a
particular set of observations, such as a single region of the country or just one type of
construction. We address this question by augmenting the previous regression with variables
formed by interacting the year effects with three other sets of factors: the building-type dummies
defined above, MSA population dummies, and geographic dummies for the nine Census Bureau
22
To examine whether the year effects reflect macroeconomic conditions, we added two explanatory variables to the
regression: the unemployment rate and the change in private payroll employment. Both variables are measured in
the project's MSA in the month when project planning was initiated. Neither variable was statistically significant,
and the year effects were little changed by adding these variables. In section IV below, we present some anecdotal
evidence that the upward trend in the year effects could be related to increased regulatory scrutiny of commercial
development projects.
- 15 -
divisions. To form the population dummies, we grouped the MSAs in our sample into the 25
most populous MSAs, the rest of the highest population quartile, the second quartile, and the
combination of the third and fourth quartiles. One variable from each set of these dummies must
be omitted to avoid perfect collinearity with the baseline year dummies. We omitted office
buildings, the largest 25 MSAs, and the South Atlantic Census division (which contains Atlanta,
the omitted MSA in the original regression). In this specification, the year dummies without any
interactions represent the year effects for office buildings in the largest MSAs in the South
Atlantic region. The interaction terms show the deviations from this baseline set of year effects
for projects with different characteristics.
We summarize the results in table 6 and report the underlying coefficient estimates for
the plan-year effects in the appendix.
23
The first column shows the change in the year effect
between 1999 and 2010, the endpoint years for our sample. This comparison, however, may not
adequately reflect the underlying trend in time-to-plan lags if the year effects for individual years
are volatile. To address this possibility, the second column presents the difference between the
average year effect in the first three years of the sample and that in the final three years.
As shown in the first column, planning lags rose for all four types of buildings over the
sample period, with increases of about 7 months for hotel projects, slightly more than 4 months
for office and warehouse projects, and 2½ months for retail stores. In addition, planning lags
increased 3 to 5 months for each of the MSA population groups. All of these increases are
statistically significant. Regionally, however, the results for the uptrend in planning lags are
more varied. Planning lags rose more than 8 months on the Pacific coast and 4 to 5 months in
the Mountain states and along the Middle and South Atlantic coast. These changes are all
significant at the one-percent level. In contrast, the planning lag rose much less in the four
23
The complete results for this augmented regression can be obtained from the authors on request.
- 16 -
central regions and New England, and none of these changes is significant. When we average
the three years at the beginning and end of the sample period, the increase in the year effects
becomes significant in New England and two of the central regions, but otherwise the results do
not change notably. All told, we find that the shift toward longer planning lags was concentrated
in the Far West and on the East coast but encompassed all types of buildings and MSAs of all
sizes.
24
D. Summing Up: The Full Distribution of Planning Times
Thus far, we have explored a variety of factors that affect planning times, generally from
the perspective of a standardized baseline project. Now we take a more comprehensive view and
ask: "What is the full distribution of planning times across all the projects in our sample?" The
construction of this distribution would be straightforward if we knew the true time to plan for
each project. However, we do not observe this information because of the six-month interval
reporting in the data and the right-censoring for projects still in the planning phase at the end of
the sample period. Given both of these measurement issues, we can only place bounds on the
true time to plan for a given project.
Despite this limitation at the project level, we can use results from our interval regression
to construct an overall distribution that reflects the variation within these known bounds.
Specifically, we form a notional planning lag for every project equal to the fitted value from the
regression plus a random draw of the error term from a truncated normal distribution consistent
with these measurement bounds, where the error variance is taken from the fitted regression. We
then assemble an overall distribution from the notional planning lags.
24
One question is whether these results are driven by the severe 2007-09 recession and the subsequent weak
recovery, which could have caused developers to delay the transition from the planning phase to the construction
phase of their projects. If this were the case, the null hypothesis of equal year effects would not be rejected for tests
that end in 2007. In fact, we found that the results from tests through 2007 were similar to those in table 6, showing
that the uptrend in the year effects existed before the recession.
- 17 -
As shown in the top panel of figure 2, this distribution of planning times is extremely
wide and sharply skewed to the right. The long right-hand tail reflects, in large part, the
influence of projects that have had deferrals –– recall from table 3 that deferral adds, on average,
more than two years to the planning period. This figure also illustrates the importance of
including censored projects in our sample. These projects, represented by the dark portion of the
bars, are concentrated in the right-hand part of the distribution and account for the vast majority
of projects with planning times of 60 months or more. Hence, excluding these cases would cause
projects in the upper portion of the planning lag distribution to be substantially under-
represented.
The distribution in the top panel counts the number of projects in each time-to-plan
bucket and does not distinguish between small and large projects. The bottom panel, in contrast,
weights each project by its share of the total cost of all projects in the sample. This cost-
weighted distribution shows the planning time for each dollar of construction spending and thus
is a more appropriate measure for assessing the macroeconomic consequences of planning lags.
As shown, the cost-weighted distribution is skewed even more sharply to the right than the
unweighted distribution. Given the long right tail, the mean cost-weighted time-to-plan lag is
more than 28 months. Even the typical (i.e. median) cost-weighted project has a time-to-plan lag
of 18 months. These statistics indicate that commercial buildings generally have a lengthy
planning period before any construction dollars are spent.
Table 7 provides additional detail about mean time-to-plan lags along two dimensions:
the influence of deferred projects and differences across types of buildings. First, the table
shows that deferrals are an important factor behind the lengthy mean planning lags. Excluding
projects with any period of deferral shortens the unweighted mean lag from about 17 months to
about 14 months for the aggregation across all building types. The effect of excluding deferred
- 18 -
projects on the cost-weighted mean lag is even greater. Second, among the four types of
buildings, hotels have the longest mean planning periods — roughly 8 to 9 months longer than
office, retail, and warehouse projects on an unweighted basis and as much as 14 months longer
with cost weighting. Much of this difference owes to the differential effect of deferrals across
the four types of buildings. As can be seen, excluding deferred projects cuts the differential
about in half on an unweighted basis and eliminates most of the gap with cost weighting. The
differences that remain mostly reflect the relatively large scale of the typical hotel project.
IV. INTERPRETATION AND ADDITIONAL RESULTS
This section takes a closer look at two key results from section III: the wide variation in
planning times across MSAs for a baseline project and the upward trend in planning times over
our sample period. In particular, we explore whether differences in land-use regulations — as
measured by the Wharton survey on residential land-use regulation reported in Gyourko, Saiz,
and Summers (2008) — are associated with the variation in planning lags. We also summarize
what we learned from our own consultations with industry experts on changes in planning
periods over time.
A. Wharton Survey on Residential Land-Use Regulation
The Wharton survey asked officials in roughly 6900 municipalities across the country to
provide information about their process for regulating residential land use and about the
outcomes of that process.
25
The survey was mailed in June 2004, and responses were received
from about 2650 municipalities, which represent a finer level of geography — Census places
than the MSA level. Gyourko, Saiz, and Summers (2008) used the results to create an overall
25
The Wharton survey did not collect information on land-use regulations for commercial property. In the absence
of such information, we assume that the regulations for residential land use are a good proxy for the unobserved
regulations on the commercial side. This assumption seems reasonable in that the rules governing each type of
property likely would reflect general community preferences toward development.
- 19 -
index of the stringency of land-use regulation in each Census place, along with eleven separate
component indexes.
Table 8 describes the eleven components of the aggregate index. The first four
components pertain to the length or intensity of the project approval process. The next four
components reflect the local rules that define permissible development activity. The final three
components measure the extent of local political influence on development, state-level political
involvement in local project decisions, and the tendency of the courts to uphold local land-use
regulation. Both the overall index and all the components are defined so that higher values
correspond to a tighter regulatory environment.
B. Variation in Planning Periods across Localities
To assess these regulatory effects, we re-ran the initial regression from section III using
fixed effects for Census places rather than the MSA fixed effects. After accounting for missing
or miscoded location information in the Pipeline database, the dataset for this regression included
74,409 projects and 5,984 places. However, most of these places had only a handful of projects,
so we ran the regression with separate fixed effects for the 1,712 places that had at least ten
projects and with a single catch-all fixed effect for all the other places. Recall that the fixed
effect represents the estimated time-to-plan lag in a given locality for our baseline project. After
setting aside the places that had no Wharton survey data and those in the catch-all group, we
regressed the fixed effects in the remaining 666 places on either the overall Wharton index or the
individual components of the index.
26
In each case, we estimated the second-stage regression in
26
We omit the local assembly index because that variable has no variation across the places with projects in our
sample.
- 20 -
two ways –– first without weights on the individual places and then by weighting the data for
each place by its share of the total project cost in the sample.
27
The results are reported in table 9. Regardless of whether we weight the data, the
estimated coefficient on the aggregate Wharton index is insignificant and the regression R
2
is
essentially zero. However, when we unpack the components of the aggregate index, the
explanatory power of the regression increases, especially for the cost-weighted regression. In
that regression, two components have significant positive coefficients and four have significant
negative coefficients. Among these six components, we focus on the coefficient on the approval
delay index (ADI) because we believe it is the only one with a straightforward interpretation.
The ADI measures the length of the review process in a locality and thus can be compared to the
fixed effects to see if both tend to be longer in the same places. The positive coefficient in the
regression provides evidence of a link between the regulatory review process and planning
timelines. Given the coefficient estimate, moving from the 1
st
percentile to the 99
th
percentile of
the ADI distribution raises the planning time for a given place by 7 months, with a tight
confidence interval. This result suggests that the length of the review process is associated with
a substantial part of the cross-sectional variation in planning times.
Unlike the ADI, the other significant index components are not measures of the time
required for planning review but instead characterize aspects of the regulatory environment that
could influence planning times. Because of the reduced-form nature of the regression, their
channels of influence are unclear. For these other index components, we can conclude only that
the regulatory environment is correlated ― in possibly complex ways ― with planning
timelines.
27
As shown in Saiz (2010), the stringency of land-use regulation, as measured by the Wharton index, reflects a
variety of characteristics of each locality and thus is endogenously determined. Accordingly, the regressions
estimated here have no structural interpretation and are intended only to assess whether project planning lags are
correlated with regulatory variables.
- 21 -
C. Planning Periods over Time
Although most of the information collected from the Wharton survey is cross sectional,
the survey includes a few questions about changes over time. In particular, one question asks:
"Over the last 10 years, how did the length of time required to complete the review and approval
of residential projects in your community change?" The possible responses are "no change,"
"somewhat longer," and "considerably longer," with separate responses for single-family and
multifamily projects. The question did not allow respondents to indicate that review periods had
become shorter. Because of this asymmetry, we cannot use the responses to examine our finding
that planning times became longer, on average, for the nation as whole. However, by comparing
the responses across Census divisions, we can assess whether the Wharton survey provides
independent confirmation of our finding that the shift toward longer planning periods was
concentrated on the East Coast and in the West.
To do this, we created an index of the Wharton responses at the Census division level.
For each of the 666 places in the Wharton regression sample, we converted the responses of "no
change," "somewhat longer," or "considerably longer" to values of zero, one, or two,
respectively, and then averaged the values for single-family and multifamily projects. Next, we
aggregated the results to the Census division level in two ways –– first as an unweighted average
of the included places and then by weighting each place by its share of the number of Pipeline
projects in that division. The unweighted average captures the general perception among the
survey respondents in each Census division, but it makes no allowance for differences in the
importance of each Census place to overall activity. Weighting each place by its number of
projects helps on the latter score, but a potential downside is that it emphasizes the views of
some survey respondents more than others, even though this weighting does not reflect their
- 22 -
degree of expertise about the regulatory review and approval process. On a priori grounds, we
could not see a clear case for one method over the other, so we tried both.
We regressed the 1999 to 2010 change in the plan-year effect by Census division on each
of the two Wharton proxies for the change in review and approval times. The results differed
across the two Wharton measures. The unweighted measure has a significant positive
relationship across Census divisions with the change in the estimated plan-year effects. In
contrast, the project-weighted measure shows a much looser and insignificant positive
relationship. Overall, these results provide limited confirmation that the regional pattern of
changes in planning lags is consistent with the regional pattern implied by the responses to the
Wharton question about changes in the length of review and approval times.
To gain further perspective on the upward trend in planning durations, we consulted with
firms that are directly involved in real estate development and with informed industry observers.
Although some of the comments reflected conditions across the country, a substantial fraction of
the real estate firms we contacted work primarily in the Washington, D.C. area, so the responses
are skewed somewhat toward that market.
An overwhelming majority of these contacts indicated that planning timelines had
lengthened over our sample period, consistent with our econometric results. In addition, several
contacts noted that the trend toward longer planning periods had started a decade or more before
the beginning of our sample period. Among the factors cited for this trend, by far the most
common was that the regulatory process for the review and approval of construction projects had
become more time-consuming. The specific features of the regulatory process seen as
contributing to this trend included greater citizen involvement in project review, tougher
environmental standards, and an increase in the number of government agencies whose approval
is required. Of course, it is important to emphasize that, even if changes in land-use regulations
- 23 -
do account for the increase in planning lags over time, we are not able to assess whether these
changes reflect a shift to over-regulation, a catch-up from too light regulation, or a change over
time in the optimal amount of regulation.
V. CONCLUSION
Gestation lags have long been understood to be an important feature of the investment
process. However, previous research has focused on the time-to-build part of the gestation
period and has provided very little information on the earlier time-to-plan lag. In addition, most
of what we know about gestation lags has come from indirect inference in structural models
estimated with aggregate data. Only a handful of studies have estimated gestation lags using
project-level information.
This paper addresses both of these limitations. We estimate time-to-plan lags for
commercial construction projects using a rich project-level dataset that allows direct observation
of these lags. Our analysis demonstrates that time-to-plan lags for commercial construction
projects are long, averaging about 17 months when we aggregate all the projects in the dataset
without regard to size. When we weight the projects by their construction cost — which is
needed to measure the average planning time for a given dollar of commercial construction
outlays — the average lag rises to more than 28 months.
Our results also show that the distribution of time-to-plan lags spans a wide range, with
an especially long right-hand tail. The characteristics of the building to be constructed and its
location account for part of this variation, while project deferrals also contribute importantly to
the long tail. Another key result is that time-to-plan lags increased by several months, on
average, over the 1999-2010 period that we study. This lengthening occurred for all types of
buildings, in MSAs of all sizes, and in most regions of the country. Finally, we find that
- 24 -
differences in the regulatory environment across jurisdictions are associated with the cross-
sectional variation in time-to-plan lags, and we present some anecdotal evidence that the upward
trend in planning lags may be related as well to the regulatory review process. As noted, our
results do not say whether the increase in time-to-plan lags reflects a move toward or away from
the optimal amount of regulation.
These results contribute to the literature in both macroeconomics and urban/real estate
economics. Macroeconomists can use the results to calibrate business cycle models and to help
specify the lag structure in models of investment spending. For urban and real estate economists,
our findings provide new information on the geographic variation in planning periods for
commercial real estate projects and on the influence of the regulatory review process at the local
level.
The Pipeline database is a valuable source of information about the planning process for
commercial construction projects. We know of no similar data for other types of investment
spending. Accordingly, the Pipeline data have the potential to provide new insights into the
factors affecting firms’ decisions to continue, defer, or abandon investment projects. In research
in progress, we are using the Pipeline data to study the effect of uncertainty on these decisions in
the commercial real estate sector.
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- 27 -
Table 1
Summary Statistics: Type of Building, Type of Construction, and Location
Percent of
observations
Percent of
construction cost
Type of building
Office
33.7
39.8
Retail
42.5
25.8
Warehouse
17.9
17.1
Hotel
5.9
17.3
Type of construction
1
New structure
95.1
93.1
Addition
7.1
7.3
Alteration
5.7
4.1
Conversion
1.0
0.5
Census Division
New England
5.4
5.1
Middle Atlantic
10.2
15.0
South Atlantic
23.8
21.6
North Central
2
17.9
16.7
South Central
3
18.5
13.2
Mountain
11.5
11.6
Pacific
12.7
16.8
MSA population
Top 25 MSAs
39.0
52.0
Rest of first quartile
49.6
40.1
Second quartile
7.0
4.6
Third and fourth quartiles
4.4
3.2
Note: Based on 82,303 projects with planning dates recorded between 1999 and 2010. See the
text for details about the construction of the sample.
1. A given project may encompass multiple types of construction.
2. Combination of East North Central and West North Central.
3. Combination of East South Central and West South Central.
- 28 -
Table 2
Summary Statistics: Project and County Characteristics
Variable Mean
Percentile of distribution
1
st
99
th
Project characteristics
Number of buildings
1.5
1
10
Number of floors
1.8
1
12
Construction cost (millions of 2005 dollars)
5.6
.2
64.4
Square footage (thousands)
59
2
600
Cost per square foot (2005 dollars)
110
21
466
Distance from city center (miles)
14
1
66
County characteristics (in year 2000)
Housing density (units per square mile)
626
11
11,675
Urban share of population (percent)
86
33
100
Homeowner share of occupied units (percent)
67
27
85
Median household income (thou. of dollars)
46
28
74
Median home price (thou. of dollars)
129
58
361
High-income share (percent of households)
1
13
4
35
Note: Based on 82,303 projects with planning dates recorded between 1999 and 2010. See the text for details about
the construction of the sample.
1. Share of households with income above $100,000.
- 29 -
Table 3
Regression Results: Baseline Planning Lag and Effects of Characteristics
Variable Linear effect Quadratic effect
Constant (planning lag for baseline project)
16.21*
(.68)
Type of building (omitted: office)
Retail
.58*
(.14)
Warehouse
-.18
(.20)
Hotel
.85*
(.31)
Type of construction (omitted: new structure)
Addition
-1.20*
(.20)
Alteration
-.09
(.30)
Conversion
-.42
(.79)
Other project characteristics
Ever deferred
24.92*
(.37)
Ever deferred * square footage
.016*
(.0041)
Ever deferred * (square footage)
2
-1.58e-6
(1.96e-6)
Number of buildings
.74*
(.096)
-.0015
(.0012)
Number of floors
.89*
(.084)
-.017*
(.0024)
Square footage
.0071*
(.0010)
-3.36e-8
(4.87e-7)
Cost per square foot
3.49*
(.84)
-.120
(.133)
Distance from city center
-.0084
(.0096)
6.6e-5
(7.5e-5)
County characteristics
Housing density
-1.03e-5
(2.22e-4)
-4.64e-9
(5.14e-9)
Urban share of population
1.62
(2.32)
-1.20
(1.83)
- 30 -
Table 3 (continued)
Regression Results: Baseline Planning Lag and Effects of Characteristics
Variable Linear effect Quadratic effect
Homeowner share of occupied units
-11.47
(11.52)
12.04
(8.28)
Median household income
-.095
(.12)
-4.26e-4
(1.35e-3)
Median home price
.063*
(.014)
-7.35e-5*
(2.61e-5)
High-income share
15.9
(10.4)
-25.4
(31.4)
Note: Estimated by a maximum likelihood procedure that accounts for right censoring and interval reporting of
the time-to-plan data. Bootstrap standard errors are shown in parentheses. A total of 500 bootstrap replications
were run; 495 drew samples in which all parameters could be identified. Asterisks indicate significance at the 5
percent level. The results for the month and year dummies are reported in table 5. The results for the MSA fixed
effects are available from the authors upon request.
- 31 -
Table 4
Effects of Change in Characteristics on Planning Duration
(in months)
Variable Total effect
95 percent
confidence interval
Bottom
Top
Project characteristics
Number of buildings
6.5
5.0
8.0
Number of floors
7.2
6.0
8.5
Square footage
4.2
3.2
5.3
Cost per square foot
1.5
0.8
2.2
Distance from city center
-0.3
-1.0
0.5
County characteristics
Housing density
-0.7
-4.3
2.9
Urban share of population
0.0
-1.0
1.0
Homeowner share of occupied units
1.2
-2.1
4.4
Median household income
-6.4
-9.8
-2.9
Median home price
9.8
6.1
13.5
High-income share
1.8
-2.2
5.8
Note: The total effect represents the change in planning duration, using the results reported in table 3, when one
explanatory variable at a time is adjusted from the 1
st
percentile of its distribution to the 99
th
percentile. The 95
percent confidence interval for each variable is calculated from the bootstrapped variance-covariance matrix of
the coefficient estimates.
- 32 -
Table 5
Regression Results for Time Effects
Month
(omitted: June)
Coefficient
Year
(omitted: 2004)
Coefficient
January
.22
(.26)
1999
-.67
(.35)
February
.39
(.23)
2000
-1.77*
(.31)
March
.32
(.23)
2001
-.32
(.32)
April
-.02
(.23)
2002
-.81*
(.27)
May
.07
(.23)
2003
-.82*
(.26)
July
.27
(.23)
2005
.74*
(.24)
August
.62*
(.23)
2006
1.12*
(.27)
September
.37
(.23)
2007
.74*
(.24)
October
.50*
(.25)
2008
2.02*
(.24)
November
.93*
(.24)
2009
1.52*
(.27)
December
.50*
(.24)
2010
2.58*
(.29)
Note: See table 3 for a description of the regression. The results for the constant term in the
regression and for the project and county characteristics are reported in table 3. The results for the
MSA fixed effects are available from the authors upon request.
- 33 -
Table 6
Change in Year-Effect Coefficients
Change, in months
1999 to 2010
1999-2001 to
2008-2010
Type of building
Office
4.2**
3.3**
Retail
2.5*
2.5**
Warehouse
4.2**
4.2**
Hotel
6.9**
5.8**
MSA population group
Top 25
4.2**
3.3**
Rest of first quartile
4.3**
2.7**
Second quartile
3.1*
2.1**
Third and fourth quartiles
4.7**
2.8**
Census divisions
Pacific
8.2**
7.0**
Mountain
4.8**
4.7**
West North Central
1.5
2.2*
West South Central
.2
.1
East North Central
.2
1.0
East South Central
1.7
2.9**
New England
1.7
2.6*
Middle Atlantic
4.6**
3.9**
South Atlantic
4.2**
3.3**
Note: ** and * indicate a significant difference at the one-percent and five-percent level,
respectively. All results are obtained from the augmented regression described in the text.
The results for office buildings, the top 25 population group, and the South Atlantic Census
division are identical because these are the omitted categories in the year-effect interactions,
so the year effects in each case are captured by the uninteracted year dummies.
- 34 -
Table 7
Mean Time to Plan
(in months)
Unweighted Cost-weighted
All projects Excl. deferred All projects Excl. deferred
All building types 17.3 13.9 28.6 20.5
Office
17.2
13.6
29.3
21.7
Retail
16.5
13.8
24.6
20.1
Warehouse
16.9
13.5
23.4
17.0
Hotel 25.2 18.1 37.9 22.4
Note: Figures shown are means of the distribution of planning lags for projects within each building type
with corrections for right-censoring and interval collection.
- 35 -
Table 8
Components of the Wharton Residential Land-Use Regulatory Index
Index Component Description
Approval delay index
An index of the time required to complete the review of
(i) residential construction projects, (ii) rezoning
applications, and (iii) subdivision applications.
Local zoning approval index
The number of local entities required to approve zoning
changes.
Local project approval index
The number of local entities required to approve new
projects.
Local assembly index
Dummy variable. Equals one if town meetings are
required to approve zoning changes.
Supply restrictions index
An index of limits on annual permit issuance and
allowable construction activity.
Exactions index
Dummy variable. Equals one if developers are required to
fund infrastructure improvements in order to build.
Density restrictions index
Dummy variable. Equals one if any area in the locality
has a minimum lot-size requirement of at least one acre.
Open space index
Dummy variable. Equals one if developers are required to
supply open space in order to build.
Local political pressure index
An index that measures (i) the degree to which various
local entities are involved in development decisions and
(ii) the importance of governmental and citizen opposition
to growth.
State political involvement
index
An index of the state-level involvement in local land-use
regulations and the enactment of state-level land-use
restrictions.
State court involvement index
An index for the tendency of appellate courts to uphold
local land-use regulation.
Note: See Gyourko, Saiz, and Summers (2008) for details.
- 36 -
Table 9
Regression of Estimated Place Fixed Effects on the Wharton Residential Land Use
Regulatory Index and Components
Variable
Unweighted
Cost-weighted
Constant
15.99*
(.25)
16.07*
(.34)
17.08*
(.16)
16.52*
(.24)
Aggregate index
.35
(.25)
-.07
(.18)
Approval delay index
.17
(.18)
1.69*
(.13)
Local zoning approval index
.41*
(.21)
.85*
(.19)
Local project approval index
.18
(.19)
-.06
(.16)
Supply restrictions index
-.04
(.23)
-.28
(.24)
Exactions index
-.13
(.20)
-.54*
(.15)
Density restrictions index
-.25
(.15)
-.35*
(.15)
Open space index
.06
(.18)
-.28
(.16)
Local political pressure index
-.15
(.15)
-.51*
(.09)
State political involvement index
.65*
(.29)
-.13
(.14)
State court involvement index
-.51*
(.26)
-.52*
(.16)
R
2
.006 .050 .0002 .356
Note: Each regression is estimated by OLS using the 666 places that have at least 10 projects. In the cost-weighted
regressions, each place is weighted by its share of total construction cost in the 666 places. The local assembly
index is excluded from the regressions because it takes the same value in every place. Robust standard errors are
shown in parenthesis. An asterisk indicates significance at the five-percent level.
- 37 -
- 38 -
APPENDIX: YEAR EFFECTS IN THE AUGMENTED REGRESSION
As described in section III, we estimated an augmented regression to assess whether the
upward trend in the year fixed effects was widespread across the sample or was limited to
specific locations or types of projects. The augmented regression includes all of the variables in
the baseline regression plus interaction terms between the year dummy variables and three sets of
other dummy variables: dummies for the type of building to be constructed by the project,
dummies for MSA population size groups, and dummies for the nine Census Bureau geographic
divisions. We estimated this augmented regression using the same maximum likelihood
procedure with bootstrapped standard errors as for the baseline regression.
Table A1 presents all the estimated coefficients that involve the year dummy variables.
Figures A1, A2, and A3 use these coefficients to plot the time series of year effects by building
type, MSA population group, and Census division.
- 39 -
Table A1
Coefficients on Year Dummies in Augmented Regression
Variable 1999 2000 2001 2002 2003 2005 2006 2007 2008 2009 2010
Uninteracted
year dummies
-2.02
(.97)
-2.13
(.86)
.30
(.85)
-.41
(.68)
.40
(.73)
2.14
(.74)
1.11
(.69)
.92
(.68)
2.02
(.72)
1.77
(.92)
2.18
(.84)
Interaction with:
Building type
(omitted: office)
Retail
1.75
(.73)
.58
(.64)
-.72
(.67)
-1.24
(.58)
-.74
(.55)
-.02
(.50)
-.75
(.55)
-.30
(.53)
.40
(.56)
-1.21
(.63)
.08
(.59)
Warehouse
-2.08
(.99)
-1.77
(.89)
-3.11
(.90)
-2.50
(.87)
-.63
(.84)
-1.10
(.77)
-.90
(.88)
-1.83
(.75)
-1.29
(.83)
-.81
(.97)
-2.12
(.86)
Hotel
-.84
(1.46)
-.16
(1.62)
-1.33
(1.54)
-1.82
(1.55)
.62
(1.55)
1.85
(1.49)
3.40
(1.35)
.10
(1.21)
.37
(1.19)
2.95
(1.30)
1.84
(1.50)
MSA population group
(omitted: top 25 MSAs)
First quartile excluding
top 25
.10
(.78)
.32
(.71)
-.19
(.76)
.53
(.65)
.09
(.62)
-.22
(.59)
-.90
(.60)
-.53
(.56)
-.94
(.58)
-.58
(.72)
.16
(.68)
Second quartile
1.01
(1.13)
1.05
(1.09)
-.17
(.94)
2.90
(.94)
.22
(.80)
-.25
(.81)
.41
(1.01)
-.74
(.81)
-1.38
(.84)
-.21
(.91)
-.09
(.84)
Third and fourth quartiles
-1.97
(1.14)
.45
(1.13)
-.72
(1.25)
-1.04
(1.09)
.95
(1.01)
-.32
(1.17)
-.07
(.96)
-.27
(.89)
-1.65
(1.11)
-.45
(1.21)
-1.44
(1.05)
Census Division
(omitted: South Atlantic)
Pacific
-.73
(1.00)
-.88
(.96)
-.31
(.99)
.44
(.96)
.47
(1.00)
-.40
(.93)
3.51
(1.00)
2.39
(.88)
2.65
(1.02)
3.43
(1.28)
3.24
(1.16)
Mountain
1.03
(1.13)
.65
(.93)
.09
(1.04)
.05
(.92)
-1.85
(.85)
-2.05
(.76)
.78
(.78)
1.05
(.79)
1.80
(.84)
2.63
(.96)
1.68
(1.02)
West North Central
3.26
(1.40)
1.25
(.94)
1.30
(1.28)
-.13
(.90)
-1.21
(.72)
-2.37
(.73)
.71
(1.09)
1.29
(.83)
2.03
(.97)
-.00
(1.29)
.58
(1.03)
West South Central
3.85
(1.18)
2.29
(1.11)
2.27
(.98)
1.22
(.87)
-1.19
(.84)
-2.71
(.78)
-.46
(.76)
-1.31
(.71)
-1.03
(.78)
.03
(.98)
-.11
(.79)
East North Central
2.48
(1.04)
.55
(.84)
.45
(.85)
-.55
(.69)
-2.43
(.64)
-2.38
(.69)
-1.07
(.61)
-.05
(.63)
-.09
(.69)
-1.62
(.83)
-1.55
(.77)
East South Central
2.28
(1.11)
-.75
(.96)
-1.10
(.83)
-.23
(.82)
-1.88
(.73)
-1.06
(.88)
.63
(.64)
1.02
(.70)
.35
(.74)
-.98
(.93)
-.20
(.89)
New England
4.38
(2.30)
1.11
(1.29)
1.57
(1.25)
-.16
(1.00)
-1.24
(.93)
-.98
(.98)
1.23
(.93)
.89
(.84)
1.01
(.92)
2.23
(1.20)
1.88
(1.09)
Middle Atlantic
2.16
(1.09)
1.49
(1.08)
1.26
(1.11)
1.49
(1.08)
-.08
(.83)
1.10
(.89)
3.20
(.87)
2.27
(.77)
2.44
(.79)
1.70
(.87)
2.58
(1.01)
Note: Estimated by a maximum likelihood procedure that accounts for right censoring and interval reporting of the time-to-plan
data. Bootstrap standard errors are shown in parentheses. A total of 500 bootstrap replications were run; 492 drew samples in
which all parameters could be identified. Shaded fields signify that the coefficient is significant at the 5 percent level, with blue
for negative coefficients and yellow for positive coefficients. The explanatory variables omitted from this table include a
constant, month-of-year dummy variables, MSA dummy variables, and the full set of project and county characteristics. Year
dummies for 2004 are omitted from the regression to avoid perfect collinearity.
- 40 -
- 41 -