Upload
nguyendan
View
220
Download
2
Embed Size (px)
Citation preview
1
Estimating Economic Impacts of Irrigation Water Supply Policy Using Synthetic Control Regions: A Comparative Case Study
Cameron Speira* and Eric Stradleya,b
aNOAA, National Marine Fisheries Service Southwest Fisheries Science Center Fisheries Ecology Division 110 Shaffer Road Santa Cruz, CA 95060 bWelch Consulting 1090 Vermont Ave. NW, Suite 900 Washington, DC 20005 *Corresponding Author. Tel.: +1 831-420-3910; fax: +1 831-420-3977. Email address: [email protected]
**DRAFT** Please do not cite or distribute without permission from the corresponding author
April 2017
2
Estimating Economic Impacts of Irrigation Water Supply Policy Using Synthetic Control Regions: A Comparative Case Study
Abstract
We evaluate whether reductions in irrigation water deliveries from large, centrally-
operated water projects to farms in the California’s San Joaquin Valley resulted in
adverse economic impacts on the local economy. These reduced water deliveries resulted
from both drought conditions and instream flow requirements for protected species
habitat. Climate change, increased municipal demand, and more acute needs for instream
flow for environmental purposes will force communities in the study area and elsewhere
to cope with reduced irrigation water supply. We employ synthetic control methods to
construct a control region in to compare employment and wage outcomes in affected
areas to unaffected areas. This comparison is used to generate empirical estimates of the
magnitude of employment and wage impacts resulting from reduced irrigation water
supply from large, government-run supply projects. Our results indicate some direct
impacts in the form of lower agricultural employment and wage income concentrated in
the two of the four affected counties. We are unable to detect evidence of impacts to the
wider, non-agricultural economy in terms of employment and wage income.
Key Words: drought; irrigation; water supply; economic impacts; endangered species;
synthetic control methods
3
1. Introduction
Agricultural areas in the western United States and other arid regions face the prospect of
reduced irrigation water supply because of drought, increased competition from urban
uses, or greater emphasis on instream flow to meet environmental goals. Local
communities are concerned that reduced irrigation water will have significant economic
impacts by reducing productive acreage and in turn reducing associated economic
activity (e.g., demand for complementary inputs such as labor, supply of farm products to
processors, income spent in the wider community). In this article, we examine
employment and income effects to the local economy of reduced water deliveries from
federal and state water projects to irrigation districts in California in 2007, 2008, and
2009. We employ a quasi-experimental approach where we compare employment and
wage income outcomes in areas where water supply was restricted to a synthetic control
region constructed from counties that were not affected by such restrictions.
Farming communities are concerned about the impact of reduced irrigation water supply
on the local economy. For example, Hanak (2005) finds that 12 out of 34 counties
sampled in California enacted ordinances restricting or prohibiting sale of irrigation water
out of the county in reaction to implementation of a water market in the early 1990’s.
Sunding et al. (2002) present a conceptual framework of the economic impacts of
reduced water supply that describes profit maximizing production decisions by
agricultural producers that are then aggregated into the region of interest. Reducing
4
irrigation water supply increases the severity of the water input constraint and induces
various production responses, including alternative crop mixes, obtaining water from
other sources (e.g. groundwater or transfers), or changing irrigation technology. These
responses change the regional output of agricultural goods and the regional demand for
inputs to agricultural production. To the extent that reduced irrigation water supply
reduces agricultural production and input demand (e.g. for labor and agricultural
services), then regional income and employment are reduced via multiplier effects.
Previous studies have attempted to estimate local economic impacts, in terms of
employment and income, of reduced irrigation water supply. Many of these studies
employ input-output models for a portion of the analysis (Llop 2013). Howe et al. (1990)
use an input-output model to estimate the economic impacts (employment and income
losses) from transfers of irrigation water from the Arkansas River basin in Colorado to
urban use. They estimate the number of acres potentially fallowed as a result of proposed
water transfers and evaluate several scenarios that differ according to assumptions made
about resultant changes in crop mix and acreage. Howe and Goemans (2003) perform a
similar analysis for water transfers in the South Platte and Arkansas basins in Colorado.
Later studies combine programming models, including the positive mathematical
programming approach (Howitt 1995), that determine optimal crop mix and input usage
with input-output models that calculate changes in income and employment. Other
studies construct production functions and simulate labor use and farm income (Maneta
et al. 2009, Iglesias 2003, Frisvold et al. 2012) or general equilibrium models (Seung et
5
al. 2000). Cai et al. (2008) analyzes the substitutability of water and labor via a basin-
scale simulation model, as well as empirically estimated farm-level production functions.
The existing studies on the effects of reduced water supply on employment typically rely
on simulation-type models that specify a production function or use multipliers to relate
changes in factor availability to employment. These studies are generally performed ex
ante in order to evaluate the effects of a proposed policy. An alternative approach is to
estimate the effects of an implemented policy ex post by comparing the observed
outcomes of interest (generally employment and income) to outcomes in a control group.
Frondel and Schmidt (2005) and Greenstone and Gayer (2009) present examples of
quasi-experiments and recommend increased use of these techniques in the analysis of
environmental policy. A substantial literature on program evaluation has developed in
the last two decades that focuses on testing for significant effects from policy and is
based on econometric methods and observed data. In our study, we use the synthetic
control method proposed by Abadie et al. (2010) to estimate the economic effects of
reduced irrigation water supply in the San Joaquin Valley using other counties as control
groups. The San Joaquin Valley of California offers a particularly compelling setting in
which to study the effects of reduced irrigation water supply. The unusually dry three-
year period of 2007-2009 combined with new restrictions on irrigation water use in 2009
to protect habitat for threatened fish species to result in substantial reductions in water
delivered to farms. This triggered widespread concern over the economic impacts on
local communities and sparked debate over the role of federal and state endangered
6
species acts. These issues are ongoing as California and national stakeholders debate a
$25 billion plan to upgrade water supply infrastructure and restore fish habitat.
We examine two research questions: 1) did changes in water supply induce a shift in the
demand for farm labor and, if so, what is a reasonable estimate of the magnitude of this
shift and 2) did water supply shocks result in indirect and induced effects to the wider
regional economy beyond the agricultural sector? We compare employment and wage
income in affected counties in the San Joaquin Valley to synthetic control regions
constructed from other areas in California. We find evidence of potential farm
employment impacts on the order of 5,500 jobs concentrated in two counties in 2009 as
well as potential farm wage income impacts in one county in all three years of the
irrigation water supply shock. We are unable to detect any significant impacts to the
wider, non-agricultural economy.
2. Description of the Study Area: California’s San Joaquin Valley
The San Joaquin Valley of California (SJV) is one of the world’s most productive
farming regions. Agricultural production is dependent on irrigation water, much of
which is imported over relatively long distances from other parts of the state. For three
years, 2007-2009, the SJV was subject to much lower allocations of irrigation water due
to an extended drought and, to a lesser extent, new restrictions designed to improve
7
instream flow conditions for protected fish species. It is this period that is the subject of
our study. Figure 1 is a map of California with our study area highlighted.
Federal and state government water projects capture and store water in northern
California, where runoff is relatively abundant, and convey it to the Sacramento-San
Joaquin River Delta (the Delta) in the center of the state. Water is then pumped from the
Delta and exported to the much drier south for use by farms in the SJV and urban users.
The Delta is the source of drinking water for more than 25 million people and provides
irrigation water for over 4 million acres of highly productive farmland (ICF International
2012). Two entities pump water from the Delta for delivery to a large portion of the
irrigated acreage in the SJV: the Central Valley Project (CVP), operated by the U.S.
Bureau of Reclamation (USBR), and the State Water Project (SWP), operated by the
California Department of Water Resources (DWR). The projects move water south for
delivery to irrigation districts within the SJV. Irrigation districts within these projects are
divided into classes based on the source of their water supply and the seniority of water
rights. Different classes of contractor receive different priority in times of shortage;
therefore the effects of water supply restrictions are unevenly distributed throughout the
region. Water supply reductions from 2007-2009 were concentrated in southern and
western portions of the SJV, particularly Fresno, Tulare, Kings, and Kern Counties,
which receive large quantities of water, have junior allocation priority according to water
law, and are particularly dependent on imported water.
8
The Delta is also the largest estuary on the west coast of the United States and provides
critical habitat for several species of fish protected under federal and state endangered
species statutes, particularly Delta smelt, Chinook salmon, and steelhead trout. From
2007 through 2009, this region suffered an intense drought, with runoff in the Delta
watershed at less than two-thirds of long-run averages (DWR 2010). Two federal
agencies, the US Fish and Wildlife Service (FWS) and National Marine Fisheries Service
(NMFS), are responsible for monitoring the effects of export of water from the Delta and
for prescribing conditions to ensure adequate habitat for several species protected under
the Endangered Species Act (ESA). FWS issued new rules designed to protect Delta
smelt that limited the quantity of water available for irrigation and which first took effect
in time for the 2009 irrigation season. Water exports from the Delta were reduced by 40
percent (2.4 million acre-feet) relative to average exports from 2001-2006. The
Congressional Research Service estimated that about 20-25 percent of this reduction was
due to endangered species policy, with the remaining reduction proportion due to low
runoff and below average reservoir storage (Cody 2009).
Table 1 shows the magnitude of the water supply shock in our treatment areas in 2007,
2008 and 2009. For CVP contractors in our affected areas, primarily in Fresno and Kings
Counties, there were minimal changes in deliveries (compared to mean values for the
previous six years) in 2007, but substantial reductions in 2008 and 2009. For SWP
contractors, primarily located in Kern and Kings Counties, 2007 saw an approximately 20
percent reduction in deliveries followed by nearly 70 percent reductions in deliveries in
9
2008 and 2009. For comparison, Table 1 also shows surface water deliveries by federal
projects to other parts of California that are potential control areas. Some of these control
areas, particularly the Sacramento Valley, were also subject to substantial reductions due
to dry conditions. However, reductions in the San Joaquin Valley were much greater
during the treatment period. Our strategy to identify the economic impacts of the water
supply shock in the SJV is to compare outcomes in the SJV to other areas. To the extent
that all control areas experience drier than normal conditions during the treatment period,
our estimates may understate the full effects of reduced deliveries relative to previous
year. However, the magnitude of the supply shock across treatment and potential control
areas indicates that we should be able to identify the effects of conditions unique to the
SJV including watershed-specific low runoff, low reservoir storage levels, and fish
habitat considerations. Note that in this study we do not estimate the impacts of low
runoff conditions and habitat protection separately. Rather, we are only able to estimate
the effect of the aggregate reduction in water supply in each year. Early ex ante estimates
of the economic impact of conditions in 2009 in the SJV ranged from 10,000 to 80,000
lost jobs, including indirect and induced impacts (for the earliest initial estimates see
Howitt 2009a). The economic impact of this water supply reduction has been the subject
of considerable debate, including congressional hearings, proposed laws to temporarily
suspend the ESA, and public outcry1.
Figure 2 plots project water deliveries (CVP and SWP) and farm employment in the four of
the SJV counties most affected by the water supply shock of 2007-2009: Fresno, Tulare,
10
Kings, and Kern. USBR and DWR report deliveries at the irrigation district level. To
generate county-level deliveries we used GIS software to overlay CVP and SWP irrigation
districts on county maps. In cases where districts spanned multiple counties, we allocated
deliveries according to the proportion of irrigation district land area in each county.
Deliveries of project water to irrigation districts in all four counties dropped during the
study period. Large declines in farm employment are also evident in three of these
counties, though the declines are not exactly concurrent with water supply changes and are
preceded by large employment increases.
3. Synthetic Control Method
Abadie et al. (2010) and Abadie and Gardeazabal (2003) propose a synthetic control
method that constructs an estimate of the outcomes that would have occurred in the
absence of the policy (i.e, a credible counterfactual case) from a combination of multiple
control units. The effect of the policy is then estimated by comparing the outcome
estimated for the synthetic control unit to the observed outcome in the exposed unit. We
use this framework to assess whether counties that were affected by reduced water
exports from the Delta had lower employment and wage income in those years than other
similar counties that were not.
The synthetic control method is part of a larger set of techniques designed to estimate
policy impacts from natural or quasi-experiments (Greenstone and Gayer 2009) where
11
outcomes in a treatment group are compared to a control group. A quasi-experimental
approach offers several advantages over a more structural approach, such as estimation of
a labor demand function. Given the small number of counties and relatively short time
series for most data, an estimated labor demand function would be forced to rely on
relatively few observations. Use of panel data would require data on wages, other input
prices, and water deliveries, all of which are difficult to obtain at the county level.
Moreover, there is some evidence of disequilibrium in the farm labor market in our study
area in recent years, which would make identification of the labor demand model difficult
(Michael 2009a, Hertz and Zahniser 2013). A quasi-experimental setup can control for
unobserved confounding variables by observing treatment and control groups that are
exposed to the same set of covariates. Also, the model does not require assumptions
regarding a specific functional form or market equilibrium.
The synthetic control approach maintains that a combination of units often provides a
better comparison for the treated unit than any single unit. In this way, it is similar to
other models, such as traditional regression-based difference-in-difference estimators,
that estimate average treatment effects using many individuals. However, synthetic
control methods have two significant advantages that make it useful for our particular
application. First, it systematically constructs a control county as a weighted average of
county from a “donor pool”, thereby removing the subjectivity involved in choosing
appropriate comparison counties. In our case, treatment and control counties will differ
in crop mix, climate, and other factors that may affect economic outcomes of interest.
12
These differences would make choosing any one (or several) control units to represent
what would have occurred in the absence of the reduction in irrigation water supply
difficult. The synthetic control method generates a single unit for comparison that
matches, as closely as possible, pre-treatment outcomes in the affected areas. Second, the
synthetic control method better addresses the type of uncertainty present in our data.
Traditional regression-based difference-in-differences estimators most often use data on a
large sample of disaggregated units (e.g., individuals) and generate standard errors that
reflect the uncertainty about aggregate values in the population. We are able to observe
aggregate outcomes (on employment and wage income at the county level), so this type
of uncertainty is not present. Our main source of uncertainty regards how well the
synthetic control group accurately mimics the behavior of the treatment units in the
absence of the reductions in irrigation water supply. We draw on the methods proposed
by Abadie et al. (2010) and Bertand et al. (2004) and use placebo tests for inference that
better reflects the type of uncertainty present in our data.
3.1 Conceptual Model Underlying Synthetic Control Approach
We use the model proposed by Abadie et al. (2010). There are J+1 counties, with county
1 being exposed to the treatment and all J other counties as potential controls. There are
T total time periods with T0 non-treatment time periods.
Yit = α1tDit + βtZi + λtμi + δt + εit (1)
13
In equation (1), Yit is the outcome of interest (employment or wage income) in county i at
time t, Dit is 0/1 indicator of whether county i is exposed to the treatment at time t, Zi is a
(rx1) vector of exogenous covariates, λt is time-varying common factor, μi is county-
specific common factor, and δt is a common intercept term that varies with time. The
parameter α1t is the treatment effect – the amount by which the outcome is shifted in the
treated county in time periods when the treatment is present.
We estimate the treatment effect α1t as the difference between the observed outcome in
treated periods (t > T0) and the counterfactual case. Abadie et al. (2010) show that the
difference between the observed outcome and a weighted average of the outcomes for all
potential donor counties (i.e., a synthetic control county) is an unbiased estimator of α1t.
, –∑ ∗ (2)
Each weight w*j is an element in W* a (Jx1) vector of weights that is chosen such that the
resulting synthetic control is the convex combination of donor counties that most closely
matches the treatment county in terms of the outcome and matching variables.
Abadie et al. (2010) choose a W* that minimizes the distance between the observed
values of the treated county and the synthetic control county, in terms of outcome and
matching variables. Specifically, let X1 be a vector containing the observed covariates
14
and the outcomes for the treatment county in the pre-treatment period: X1 = (Z1, Y11, ...,
Y1T0). Let X0 then be a matrix consisting of the observed covariates and pre-treatment
outcomes for all donor counties; X0 is a (r+T0, J) matrix where the jth column is (Zj, Yj1,
..., YjT0). The optimal vector of weights W* is chosen to minimize:
(3)
where V is any (r+T0 x r+T0) positive semi-definite matrix. Choose V such that the mean
squared error of the outcome variable is minimized in non-treatment periods.
3.2 Significance of Estimated Treatment Effects
We use cross sectional placebo tests to assess the significance of the estimated treatment
effects. These tests consist of sequentially applying the synthetic control algorithm
described above to all 25 counties in our donor pool. The difference between the
observed and synthetic outcome is a placebo test where a treatment effect is estimated
though no treatment is applied. A significant treatment effect should be large relative to
the placebo test results for the donor counties. We can generate a quantitative assessment
of our estimated treatment effect by interpreting the placebo run as a permutation test. If,
for example, our estimated treatment effect is larger than 95 percent of the placebo test
effects, then we interpret it to be significant at the 5 percent level. This follows the
permutation test methods laid out in Abadie et al.(2010) as well as Bertrand et al. (2004).
15
4. Data and Construction of Synthetic Control Regions
4.1 Data
Our data are county-level panel data for the period 2001 through 2011. We consider the
four southernmost counties in the San Joaquin Valley to be treatment areas: Fresno, Kings,
Tulare, and Kern2. We estimate the impact in each county separately to account for
differences in localized impacts. Impacts are in terms of labor market outcomes: farm
employment, farm payroll, non-farm employment, and non-farm payroll. The measures of
agricultural labor employed are estimate of the direct effects of reduced irrigation water
supply on labor demand. Nonagricultural labor outcomes are a measure of the indirect
and/or induced effects that may be transmitted through the broader economy. One
important issue to consider is the role of undocumented labor in our data. According to the
U.S. Department of Labor’s National Agricultural Workers Survey, over half of California
farm workers do not have legal work authorization. If these workers are not counted in
employment surveys, then employment numbers underestimate the number of workers
employed and, therefore, the impacts of the water supply reductions. Further, it may be that
seasonal undocumented workers represent the marginal units of labor employed, as
permanent workers would seem more likely to have legal work status. This would mean
that changes in labor demand would disproportionately affect the undocumented portion of
the labor force. We believe that the employment and compensation numbers we use
16
provide reasonable estimates of labor market impacts for two reasons. First, employment
and compensations estimates are generated in part from the Bureau of Economic Analysis’
(BEA) Current Employment Statistics (CES) Program. According to BEA, the survey
instrument should capture undocumented workers, but BEA does not know the extent to
which they are excluded3. Second, there is some evidence that workers without legal status
use fraudulent documents, which means that the status of these workers is assumed to be
legal by employers and that they are included in official counts of payroll records
(Hotchkiss and Quispe-Agnoli 2008, GAO 2005).
Synthetic control counties are constructed from a donor pool of 25 counties in California.
We use crop mix, the value of crop production per acre, three weather variables,
population density, and population. Crop mix values are the percent of county cropped
acreage in each of seven crop categories. Weights are chosen so that the synthetic control
has similar values to the treatment region in terms of these predictor variables.
Figure 3 shows employment and compensation trends for the four affected counties and
25 potential donor counties. The effects of the national recession can be seen in 2008
through 2010, particularly in the non-farm sector. These pronounced macroeconomic
effects played a role in the intense interest in the economic impacts from ESA habitat
protections in 2009. From the farm sector graphs in Figure 3 and the harvested acreages
and farm-gate value graphs in Figure 4 we see that pre-2007 trends in the donor counties
resemble those in the treatment counties, but do not match precisely. Constructing
17
synthetic control counties using pre-treatment trends and the values of matching variables
helps to construct a more plausible counterfactual. We also see a large drop in harvested
acres (though not crop value) in the affected areas relative to the donor counties in 2009.
This suggests that there may have been a strong effect from decreased water supply in the
affected area in 2009.
4.2 Synthetic Controls Weights and Predictor Variable Values
Table 2 displays the weights assigned to each control county in the constructed value of
the synthetic regions for farm employment and compensation. Table 2 shows that farm
employment for Fresno County, for example, was best reproduced by a linear
combination of Sacramento, Sutter, Monterey, Imperial, and Santa Barbara Counties.
Table 3 shows the resulting values of the predictor variables used to construct the
synthetic controls for farm employment and farm compensation. The values in Table 3
serve as one measure the analyst can use to assess how closely the synthetic control
matches the treatment county. Table 4 displays the weights of each control county in the
constructed value of the synthetic region for non-farm employment and non-farm
compensation. Table 5 shows the resulting values of the predictor values used to
construct the synthetic controls for non-farm employment and non-farm compensation.
We use the “synth” module written for Stata to implement the model (Abadie et al.
2011). Note that in creating the synthetic controls, we normalize the outcomes by the
18
mean number of cropped acres (2001-2006) in the case of farm employment and
compensation or by year 2000 population in the case of non-farm employment and
compensation. This controls for differences in the size of the counties.
5. Results
Our estimates of the effect of reduced water supply in 2007, 2008, and 2009 are the
difference between observed outcomes in each treatment county and its synthetic control.
5.1 Farm Employment and Compensation
Table 6 reports our estimates of farm employment and compensation losses for each year
of the water supply shock. Figure 5 graphs the observed values and their synthetic
controls for farm employment over time for each of the four most affected counties in our
treatment area. Farm employment losses are observed in 2009 for Fresno County and
Kern County, two of the counties most affected by reduced irrigation water supply in that
year. Farm job losses are also observed in Kings County in 2008.
The Fresno and Tulare County results require some explanation. In both cases, the
optimal synthetic control, as derived by the method proposed by Abadie et al. (2010) was
lower than the observed values for all years. In these two cases, we shift the calculated
synthetic control upward by the amount of the Root Mean Squared Error for the non-
19
treatment periods. This makes the estimate of job losses in Fresno and Tulare Counties
difference-in-differences (DD) estimators, as we are not comparing observed versus
synthetic outcomes directly, but rather comparing the difference in the treatment and
control values before and after the irrigation water supply shock.
Figure 6 plots the estimated treatment effect (the difference between observed farm
employment and the synthetic control value) for the treatment county and placebo effects
for the 25 donor counties. If the placebo results are similar to the treatment effects, we
would conclude that our estimated results are due to chance rather than a real change in
employment due to the water supply shock. Table 6 presents the rank order of the
magnitude of the estimate of treatment effects for each treated county. The estimated job
losses in 2009 in Fresno (rank of 5 out of 25 counties) and Kern Counties (rank of 4 out of
25 counties) are significant at the 20 percent and 16 percent levels. These would be treated
as not different from zero in conventional significant tests with 5 percent or 10 percent as
the cutoff values. For our purposes, however, we will interpret these results as evidence
that Delta export restrictions did induce some reduced level of agricultural employment in
portions of our study area because the plotted time series do seem to show a sharp break in
employment trends at that year. The inference results indicate that these numbers are
uncertain and that agriculture employment numbers are generated by a noisy process, which
make assigning causality to particular events difficult. Table 6 and Figure 8 show
significant farm compensation losses ($19 million – $35 million) in 2007, 2008, and 2009
for Kern County. No other significant farm compensation losses are observed.
20
Though the estimated treatment effect for Kings County show no farm employment impact,
examination of the absolute level of farm employment reveals difficult to interpret
employment trends. In 2005, 2006, and 2007 farm employment in Kings County increased
substantially, eventually being about 25 percent higher than in 2001-2004. In 2008 farm
employment dropped precipitously, but back down to levels near the trend path traced by
the synthetic control. Figure 2 shows that this decline coincided with the large drop in
deliveries in 2008, indicating some negative impacts. The large run-up in employment,
however, complicates our ability to assign causality and our synthetic control is unable to
generate a significant negative impact.
5.2 Non-farm Employment and Compensation
Table 7 reports our estimates of non-farm employment and compensations losses for each
year of the water supply shock. Figure 9 graphs the observed values and their synthetic
controls for non-farm employment by county. In the case of Kings County, we construct a
difference-in-differences (DD) estimator by shifting the calculated synthetic control
downward by the amount of the Root Mean Squared Error for the non-treatment periods.
We observe non-farm employment levels in that are lower than the synthetic control in
Fresno and Kings Counties for portions of the treatment period. However, these differences
are not significant according to our placebo tests (results are plotted in Figure 10). Figure
11 graphs the observed values and their synthetic controls for non-farm compensation and
21
shows small losses in 2009 in Fresno and Kern Counties. The size of the losses is not
significantly different from zero, according to our placebo tests (Figure 12).
5.3 Comparison of Results to Other Estimated Impacts
As noted previously, the economic impacts of the water supply reductions in the San
Joaquin Valley in 2009 were the subject of intense concern and debate. Three sets of
authors produced at least eight different estimates of employment and income losses, both
ex ante and ex post. Howitt et el. released three ex ante estimate of job and income losses
between January and September 2009 that combined a hydrologic, economic optimization,
and input-output models (Howitt et al. 2009a, 2009b, 2009c). The final, corrected and
updated, version estimated job losses of 6,400 in agriculture and almost 15,000 in non-
agricultural industries. Using several sets of multipliers, Michael (2009a) made an initial
ex ante forecast of 5,000-6,500 agricultural job losses due to the water supply shock with an
additional 5,000-6,000 jobs lost in non-agricultural industries. Michael (2009a) also
proposed that labor shortages in the region may have resulted in even lower job losses, with
a lower bound at zero. Michael et al. (2010) generated ex post economic impact estimates
using similar methods as the earlier studies by Howitt et al. and Michael, but using updated
data on water availability and cropping patterns. This report estimated approximately 4,500
agricultural jobs and between 1,000-3,000 non-agricultural jobs lost. Sunding et al. (2011)
used farm payroll data similar to ours and a simple econometric time series model to
generate an ex post estimate of 5,000 agricultural jobs lost.
22
Our estimate of 5,500 jobs lost in agriculture is similar in magnitude to the ex post
estimates. Also, our results indicating that these impacts are confined to two counties,
Fresno and Kern is consistent with the results indicating intra-regional differences in
impacts in Michael et al. (2010). These differences are due to institutional and engineering
features of the project water supply system in the SJV that give lower priority to CVP
contractors on the west side of Fresno County and SWP contractors in southern/western
Kern County. In contrast to these other studies, however, we find no detectable
employment impacts in non-agricultural industries.
6. Conclusion
We examined whether reductions in water exports from the Sacramento-San Joaquin River
Delta from 2007 to 2009 caused adverse impacts the local economy in California’s San
Joaquin Valley. We compared employment and wage income data from four of the most
affected counties to corresponding synthetic control units. Our results indicate employment
losses of 5,500 agricultural jobs, concentrated in two counties in 2009. In addition, we find
wage income losses to farm employees of between approximately $20 million and $35
million in Kern County in 2007-2009, with the largest income losses occurring in 2009.
We did not detect any job or employee income effects in the wider, non-agricultural
economy. Our estimates of agricultural labor impacts are similar to ex post estimates
generated via combinations of positive math programming, input-output, and simple
23
regression models.
Our estimate of no detectable impacts to the non-agricultural labor market is in contrast to
estimates that conclude small impacts of 2,000 to 3,000 jobs. The treatment period
occurred during the U.S. recession of 2007-2009 and broader macroeconomic events may
have swamped the effects of water supply reductions. It may also indicate that multiplier
effects from water supply reductions are small.
Our results also suggest that economic impacts from water supply reduction may be subject
to a threshold effect. Substantial reductions in project deliveries were observed in the study
area in 2008, but significant employment effects were only detected in 2009. Fresno and
Kerns County actually experience absolute employment increases in 2008 and the estimated
employment effects relative to the control counties is positive. In the future, periods of
low-runoff or water storage will coincide with strong requirements for instream flow for
habitat protections. The existence of non-linear employment impacts would suggest that a
precautionary water storage management system with lower mean and variance in
deliveries could mitigate some of these impacts.
Water exports from the Sacramento-San Joaquin Delta are a controversial and ongoing
policy issue as habitat considerations for Delta smelt, Chinook salmon, and steelhead will
continue to constrain Delta exports for the foreseeable future. These restrictions are
necessary to protect a critically impaired ecosystem, but policy makers will want to know
24
the consequences for a farm economy that produces over $25 billion in output per year. As
climate change, growing demand from municipal users, and increased allocation to
environmental quality, agricultural communities will be faced with reduced quantities of
irrigation water throughout many arid and semi-arid regions. These results can help
stakeholders better understand the economic effects that occurred in this case, the first year
that new habitat considerations were a binding constraint on irrigation water supply. The
synthetic control method proposed by Abadie et al. (2010) and applied here offers a
promising method for policy evaluation of this type.
25
Footnotes
1. See items in the popular press, for example,
http://online.wsj.com/article/SB10001424052970204731804574384731898375624.html,
http://naturalresources.house.gov/news/documentsingle.aspx?DocumentID=23016, and
http://www.economist.com/node/14699639.
http://www.nytimes.com/gwire/2009/05/12/12greenwire-calif-water-agency-changes-
course-on-delta-sme-10572.html
2. Three other SJV counties (San Joaquin, Stanislaus, and Merced) also receive CVP water.
We do not include these as treatment counties because a smaller proportion of their
deliveries are subject to Delta export restrictions and because preliminary analysis indicated
no significant effects in these counties.
3. See information at the Bureau of Labor Statistics website: www.bls.gov/ces/cesfaq.htm.
26
References
Abadie, A., Diamond, A. and Hainmueller, J. 2010. Synthetic control methods for
comparative case studies: Estimating the effect of California’s tobacco control
program. Journal of the American Statistical Association 105(490), 493-505.
Abadie, A., Diamond, A. and Hainmueller, J. 2011. Synth: a R package for synthetic
control methods in comparative case studies. Journal of Statistical Software
42(13), 1-7.
Abaide. A. and Gardeazabal, J. 2003. The economic costs of conflict: A case study of the
Basque Country. American Economic Review 93(1), 112-132.
ICF International. 2012. Environmental Impact Report / Environmental Impact Statement
for the Bay Delta Conservation Plan, Appendix 1A: Primer on California Water
Delivery 3 Systems and the Delta.
Bertrand, M., Duflo, E., and Mullainathan, S. 2004. How much should we trust
Differences-In-differences estimates? The Quarterly Journal of Economics
119(1),249–275.
Cai, X., C. Ringler, and J.-Y. You. Substitution between water and other agricultural
inputs: Implications for water conservation in a River Basin context. Ecological
Economics 66(1), 38-50.
Cody, B.A., P. Folger, and C. Brougher. 2009. California Drought: Hydrological and
Regulatory Water Supply Issues. Congressional Research Service Report
R40979.
27
Department of Water Resources (DWR). 2010. California’s Drought of 2007–2009: An
Overview.
Frisvold, G. B. and Konyar, K. 2012. Less water: How will agriculture in southern
mountain states adapt? Water Resources Research 48(5),W05534.
Frondel, M. and Schmidt, C.M. 2005. Evaluating environmental programs: The
perspective of modern evaluation research. Ecological Economics 55(4), 515-526.
Greenstone, M. and Gayer, T. (2009). Quasi-experimental approaches to environmental
economics. Journal of Environmental Economics and Management 57(1), 21–44.
GAO. 2005. Immigration enforcement: Weaknesses hinder employment verification and
worksite enforcement efforts. GAO-05-813.
Hertz, T. and Zahniser, S. 2013. Is There A Farm Labor Shortage? American Journal of
Agricultural Economics 95(2), 476-481.
Hotchkiss, J.L. and Quispe-Agnoli, M. 2008. The labor market experience and impact of
undocumented workers. Federal Reserve Bank of Atlanta, Working Paper 2008-
7c.
Howe, C. W. and Goemans, C. 2003. Water transfers and their impacts: Lessons from
three Colorado water markets. JAWRA Journal of the American Water Resources
Association 39(5),1055–1065.
Howe, C. W., Lazo, J. K., and Weber, K. R. 1990. The economic impacts of Agriculture-
to-Urban water transfers on the area of origin: A case study of the Arkansas River
valley in Colorado. American Journal of Agricultural Economics 72(5),1200–
1204.
28
Howitt, R. E. 1995. Positive mathematical programming. American Journal of
Agricultural Economics 77(2), 329–342.
Howitt, R., MacEwan, D. and Medellín-Azuara, J. 2009a. Economic impacts of
reductions in Delta exports on Central Valley agriculture. ARE Update 12(3),1-4.
University of California Giannini Foundation of Agricultural Economics.
Howitt, R., MacEwan, D., Medellín-Azuara, J., and S. Hatchett. 2009b. Economic
impacts of reductions in Delta exports on Central Valley agriculture: Update
Summary, May 22, 2009. Department of Agricultural and Resource Economics,
University of California, Davis.
Llop, M. 2013. Water reallocation in the input-output model. Ecological Economics 86,
21-27.
Michael, J., Howitt, R., Medellín-Azuara, J., and MacEwan, D. 2009c. Measuring the
Employment Impact of Water Reductions, September 28, 2009. Department of
Agricultural and Resource Economics and Center for Watershed Sciences,
University of California, Davis.
Howitt, R. E., MacEwan, D., and Medellin-Azuara, J. 2011. Drought, jobs, and
controversy: Revisiting 2009. ARE Update 14(6), 1-4. University of California
Giannini Foundation of Agricultural Economics.
Iglesias, E., Garrido, A., and Gómez-Ramos, A. 2003. Evaluation of drought
management in irrigated areas. Agricultural Economics 29(2), 211–229.
Maneta, M. P., Torres, M. O., Wallender, W. W., Vosti, S., Howitt, R., Rodrigues, L.,
Bassoi, L. H., and Panday, S. 2009. A spatially distributed hydroeconomic model
29
to assess the effects of drought on land use, farm profits, and agricultural
employment. Water Resources Research 45(11), W11412+.
Michael, J. 2009a. Unemployment in the San Joaquin Valley in 2009: Fish or
Foreclosure? Business Forecasting Center, University of the Pacific.
Michael, J., Howitt, R., Medellín-Azuara, J., and MacEwan, D. 2010. A retrospective
estimate of the economic impacts of reduced water supplies to the San Joaquin
Valley in 2009. Business Forecasting Center, University of the Pacific.
Seung, C. K., Harris, T. R., Englin, J. E., and Netusil, N. R. 2000. Impacts of water
reallocation: A combined computable general equilibrium and recreation demand
model approach. The Annals of Regional Science, 34(4), 473–487.
Sunding, D., Zilberman, D., Howitt, R., Dinar, A., and N. MacDougall. 2002. Measuring
the costs of reallocating water from agriculture: A multi-model approach. Natural
Resource Modeling 15(2), 201–225.
Sunding, D.L., Formean, K.C., and Auffhammer, M. 2011. Water and jobs: the role of
irrigation water deliveries on agricultural employment. ARE Update 14(4), 1-4.
University of California Giannini Foundation of Agricultural Economics.
30
Table 1 Changes in Water Deliveries from State and Federal Water Projects to Affected and Potential Control Areas. Affected Areas Potential Control Areas
CVP
South of Delta Contractorsa
SWPSan Joaquin Valley
Contractorsb
CVP Sacramento Valley
Contractorsc
USBRColorado Aqueductd
USBRKlamath Projecte,f
Mean Deliveries (Acre-feet) 2001-2006
1,036,547 1,083,080 562,625 4,268,676 365,005
Coefficient of Variation 2001-2006
0.13 0.36 0.10 0.05 0.10
Percent Change 2007
0.00 -0.21 -0.20 -0.02 0.29
Percent Change 2008
-0.55 -0.69 -0.24 -0.04 0.29
Percent Change 2009
-0.71 -0.68 -0.35 -0.12 0.24
a. Source USBR, CVP Schedule of Historical and Projected Irrigation Water Deliveries (Schedule A-14).Includes CVP contractors in the Delta-Mendota Pool and San Luis Canal operational units. Primarily Fresno and Kings Counties. b. Source: DWR SWP Delivery Reliability Reports 2011-2013 (Appendix A, Historical SWP Delivery Tables). Primarily Kern and Kings Counties. c. Source USBR, CVP Schedule of Historical and Projected Irrigation Water Deliveries (Schedule A-14).Includes CVP contractors in the Tehama-Colusa Canal and Sacramento River operational Units. Districts are in Shasta, Tehama, Glenn, Butte, Colusa, Sutter, Yolo, and Sacramento Counties. d. Source: USBR Colorado River Accounting and Water Use Reports 2001-2011 (Diversions from Mainstream-Available Return Flow and Consumptive Use of Such Water Tables). Includes annual diversions by Palo Verde, Imperial, and Coachella Valley Irrigation Districts. Primarily Imperial and Riverside Counties. e. Source: USBR Klamath Project annual Operations Plans. Includes estimated deliveries to irrigation districts in the Upper Klamath Lake and East Side delivery areas. Districts are located in Modoc and Sisikiyou Counties in California as well as Oregon. f. Note that these figures are pre-season forecasts of delivered water and that data are available beginning 2003.
31
Table 2 Donor County Weights in Each Synthetic Control Unit: Farm Employment and Compensation Farm Employment Farm Compensation
Donor County Fresno Tulare Kings Kern Fresno Tulare Kings Kern
Sacramento 0.145 - 0.078 0.006 0.407 0.053 0.254 0.083Yolo - - - 0.174 - 0.299 - - Sutter 0.219 - 0.24 - - - 0.169 - Glenn - - 0.12 - - - 0.028 - Monterey 0.443 - - - 0.143 0.31 - - Imperial 0.096 0.115 0.272 0.075 0.266 0.246 0.302 0.121Santa Clara - 0.138 - - - - - - San Benito - - 0.012 - - - - - Tehama - - - - - - - 0.171Butte - 0.028 - - - - - 0.096Lake - 0.240 - 0.156 0.184 - - 0.24Lassen - - 0.056 - - - 0.247 - San Bernardino - - 0.149 0.121 - 0.091 - - San Luis Obispo - - 0.073 - - - - - Santa Barbara 0.096 0.480 - 0.468 - - - 0.289
32
Table 3 Predictor Variables with Observed and Synthetic Values: Farm Compensation and Employment. Fresno Tulare Kings KernVariable
Observed Farm
Employment Synthetic
Farm Compensation
SyntheticObserved
Farm Employment
Synthetic
Farm Compensation
SyntheticObserved
Farm Employment
Synthetic
Farm Compensation
SyntheticObserved
Farm Employment
Synthetic
Farm Compensation
Synthetic Population density (per sq. mile)
134.1 283.3 550.5 76.3 268.5 170.6 93.1 161.0 356.6 81.3 125.0 177.7
ln(Population) 13.6 12.6 12.7 12.8 12.5 12.6 11.8 12.0 11.9 13.4 12.6 12.0
Seasonal precipitation 77.8 191.1 223 220.7 223.1 171 141.3 165.0 185 134.6 200.3 275
Annual Cooling Degree Days
1,928.3 995.6 1,865 1,930.9 940.5 1,944 2,143.3 2,231.5 2,036 2,250.8 1,107.8 1,385
Annual Heating Degree Days
2,326.1 2,247.3 2,216 2,242.5 2,348.4 1,942 2,196.0 2,194.5 2,633 2,394.6 2,354.8 2,425
Field Crop Acreage % 15.0 5.9 11.2 19.0 2.2 8.3 41.6 7.2 9.6 7.8 4.5 3.9
Grains Acreage % 4.0 5.4 10.8 3.7 4.1 10.6 10.5 10.7 14.1 4.6 4.7 4.8
Orchard Acreage % 9.6 4.5 3.2 15.2 3.4 1.8 5.2 6.0 4.3 7.1 2.9 5.1
Rice Acreage % 0.3 7.4 1.5 0.0 0.6 2.5 0.0 10.1 6.7 0.0 1.4 2.3
Truck Crop Acreage % 12.7 13.9 9.4 0.8 7.9 14.6 4.8 7.4 7.9 3.2 8.5 5.7
Vegetable Acreage % 10.2 3.1 6.6 4.2 3.2 2.1 0.8 1.2 3.1 2.8 2.8 3.6
Pasture Acreage % 48.3 58.5 56.7 57.1 78.4 59.6 37.2 55.9 53.0 74.5 75.0 74.4
Value per cropped acre $ 1,538.9 $ 1,525.1 $ 1,176 $ 1,230.1 $ 1,033.3 $ 1,235 $ 805.5 $ 782.8 $ 855 $ 864.1 $ 864.0 $ 808
33
Table 4 Donor County Weights in Each Synthetic Control Unit: Non-farm Employment and Compensation Non-farm Employment Non-farm Compensation
Donor County Fresno Tulare Kings Kern Fresno Tulare Kings Kern
Sacramento 0.244 0.099 0.013 0.054 0.286 0.116 0.021 0.010Yolo 0.035 - - 0.009 - - 0.035 0.178Sutter 0.245 0.144 - 0.311 0.186 - 0.325 -Glenn - - 0.347 - - 0.682 - -Monterey 0.165 - - 0.028 - - - -Imperial 0.165 0.301 0.215 0.201 0.261 0.125 0.500 0.485Solano - - 0.130 - - - - -Lake - 0.408 0.041 - 0.266 - - 0.066Lassen - - 0.010 - - - 0.119 -San Bernardino 0.147 0.047 0.233 0.397 - 0.077 - -San Luis Obispo - - 0.010 - - - - 0.262
34
Table 5 Predictor Variables with Observed and Synthetic Values: Non-farm Compensation and Employment. Fresno Tulare Kings Kern
Variable Observed Non-farm
Employment Synthetic
Non-farm Compensation
SyntheticObserved
Non-farm Employment
Synthetic
Non-farm Compensation
SyntheticObserved
Non-farm Employment
Synthetic
Non-farm Compensation
SyntheticObserved
Non-farm Employment
Synthetic
Non-farm Compensation
Synthetic Population density (per sq. mile)
134.1 385.2 407.9 76.3 177.5 171.5 93.1 115.2 92.9 81.3 154.7 81.5
ln(Population) 13.6 12.8 12.1 12.8 11.7 11.2 11.8 12.0 11.6 13.4 12.8 12.0
Seasonal precipitation 77.8 182.1 244.9 220.7 255.9 252.7 141.3 197.7 141.7 134.6 142.3 134.7
Annual Cooling Degree Days
1,928 1,784 2,009 1,931 2,103 1,892 2,143 2,166 2,796 2,251 2,242 2,797
Annual Heating Degree Days
2,326 2,184 2,308 2,243 2,410 2,261 2,196 2,202 1,918 2,395 2,179 1,725
Field Crop Acreage % 15.0 9.3 10.6 19.0 7.2 8.5 41.6 6.0 8.5 7.8 6.0 7.8
Grains Acreage % 4.0 8.4 11.0 3.7 10.6 7.1 10.5 9.5 17.1 4.6 7.9 15.6
Orchard Acreage % 9.6 5.3 6.5 15.2 6.4 8.3 5.2 5.1 6.1 7.1 5.7 2.1
Rice Acreage % 0.3 8.8 6.8 0.0 4.8 13.5 0.0 6.7 10.5 0.0 9.9 1.4
Truck Crop Acreage % 12.7 9.7 7.3 0.8 6.8 3.7 4.8 5.1 11.7 3.2 6.9 11.5
Vegetable Acreage % 10.2 3.4 5.4 4.2 4.3 1.6 0.8 0.8 0.3 2.8 0.8 1.7
Pasture Acreage % 48.3 53.7 50.9 57.1 58.6 57.1 37.2 66.4 43.4 74.5 60.9 59.2
Value per cropped acre 1,539 1,078 $ 970 1,230 883 $ 678 805 605 $ 1,018 864 706 $ 913
Note: Values except for population are the mean of the pretreatment period, 2001-2006.
35
Table 6 Results: Estimated Farm Employment and Compensation Differences by Treatment County
County Year Observed
Farm Employment
Synthetic Farm
Employment
Difference
RankOrder
of Difference (out of 25)
Observed Farm
Compensation
Synthetic Farm
Compensation
Difference
RankOrder
of Difference (out of 25)
Fresno 2001-2006 46,733 46,409 321 $ 423,596 $ 425,372 $ -1,776 2007 48,100 47,060 1,040 22 454,596 $ 443,210 11,386 16 2008 48,900 48,158 742 21 500,437 474,339 26,098 19 2009 45,100 47,301 -2,201 5 535,483 518,228 17,255 17 Tulare 2001-2006 32,633 33,226 -593 344,557 346,217 -1,660 2007 35,000 34,086 914 21 359,250 332,470 26,780 21 2008 36,700 34,978 1,722 24 396,889 374,369 22,520 19 2009 36,400 35,051 1,349 21 421,875 418,741 3,134 16 Kings 2001-2006 7,383 7,318 66 108,170 111,003 -2,833 2007 9,300 6,991 2,309 24 118,354 111,560 6,794 18 2008 6,700 7,020 -320 4 130,547 121,819 8,728 18 2009 6,500 6,173 327 18 139,420 134,384 5,036 17 Kern 2001-2006 42,217 40,702 1,515 474,388 480,577 -6,189 2007 45,600 42,686 2,914 23 479,689 498,792 -19,103 4 2008 49,600 44,777 4,823 24 542,922 567,878 -24,956 3 2009 42,300 45,558 -3,258 5 625,167 660,639 -35,472 2
36
Table 7 Results: Estimated Non-Farm Employment and Compensation Differences by Treatment County
County Year Observed Non-farm
Employment
Synthetic Non-farm
Employment
Difference
RankOrder
of Difference (out of 25)
Observed Non-farm
Compensation (Thousand $)
Synthetic Non-farm
Compensation (Thousand $)
Difference
RankOrder
of Difference (out of 25)
Fresno 2001-2006 287,400 287,742 -342 $ 13,603,888 $ 13,590,215 $ 13,673 2007 306,400 306,890 -490 13 16,599,003 16,482,728 116,275 15 2008 303,000 302,393 607 15 17,019,764 16,968,505 51,260 12 2009 286,500 288,242 -1,742 11 16,366,771 16,473,854 -107,083 7 Tulare 2001-2006 105,150 106,007 -857 $ 4,858,595 $ 4,909,415 $ -50,820 2007 113,600 111,435 2,165 15 6,066,617 5,989,332 77,285 18 2008 113,600 110,621 2,979 15 6,300,385 6,214,013 86,373 16 2009 107,300 106,164 1,136 14 6,142,462 6,052,438 90,024 16 Kings 2001-2006 32,750 33,262 -512 $ 1,843,603 $ 1,858,627 $ -15,024 2007 35,600 35,770 -170 22 2,341,890 2,340,213 1,677 12 2008 37,400 35,206 2,194 23 2,473,840 2,422,913 50,927 19 2009 36,300 33,478 2,822 23 2,396,545 2,391,850 4,695 11 Kern 2001-2006 213,600 218,078 -4,478 $ 11,347,022 $ 11,616,342 $ -269,320 2007 238,700 238,001 699 11 14,657,950 14,444,850 213,100 17 2008 238,500 234,197 4,303 14 15,284,468 15,041,276 243,192 19 2009 228,100 223,050 5,050 17 14,697,859 14,720,648 -22,789 10
37
Fig. 1. Map of California with Study Area Highlighted
38
Fig. 2. Total Project (CVP and SWP) Water Deliveries and Total Agricultural Employment in the Four Affected Counties in the Study Area, 1981-2010
Sources: SWP deliveries: California Department of Water Resources, Table B-5B of Appendix B, Bulletin 132-12. http://www.water.ca.gov/swpao/docs/bulletin/12/Appendix_B.pdf. CVP deliveries: Schedule A-14 of CVP Ratebooks-Irrigation. http://www.usbr.gov/mp/cvpwaterrates/ratebooks/irrigation/2012/2012_irr_sch_a-14.pdf.
45,
000
46,
000
47,
000
48,
000
49,
000
200
400
600
800
1,0
001
,200
Wa
ter
De
live
ries
(Tho
usan
d A
cre
-fee
t)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Water Deliveries
Farm Employment
Fresno
30,
000
32,
000
34,
000
36,
000
38,
000
Far
m E
mpl
oym
ent
300
400
500
600
700
800
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Water Deliveries
Farm Employment
Tulare
6,0
007
,000
8,0
009
,000
10,
000
100
150
200
250
300
350
Wa
ter
De
live
ries
(Tho
usan
d A
cre
-fee
t)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Water Deliveries
Farm Employment
Kings
40,
000
42,
000
44,
000
46,
000
48,
000
50,
000
Far
m E
mpl
oym
ent
1,5
002
,000
2,5
003
,000
3,5
00
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Water Deliveries
Farm Employment
Kern
39
Fig. 3. Employment and Compensation Outcomes in Affected Counties and Potential Donor Counties
Sources: California Employment Development Department (Employment) and U.S. Bureau of Economic Analysis (Compensation). Note the difference in scale for Non-farm employment and compensation.
100
,000
110
,000
120
,000
130
,000
140
,000
Job
s
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Affected Counties
All Donor Counties
Farm Employment
1,2
00,0
001
,400
,000
1,6
00,0
001
,800
,000
2,0
00,0
00
Wa
ge I
ncom
e
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Affected Counties
All Donor Counties
Farm Compensation
3,5
00,0
003
,600
,000
3,7
00,0
003
,800
,000
3,9
00,0
00
Job
s -
All
Do
nor
Co
untie
s
600
,000
620
,000
640
,000
660
,000
680
,000
700
,000
Job
s -
Aff
ect
ed C
ount
ies
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Affected Counties
All Donor Counties
Non-farm Employment
220
,000
,000
240
,000
,000
260
,000
,000
280
,000
,000
300
,000
,000
Wa
ge I
ncom
e -
All
Don
or C
ount
ies
25,
000,
000
30,
000,
000
35,
000,
000
40,
000,
000
45,
000,
000
Wa
ge I
ncom
e -
Aff
ecte
d C
oun
ties
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Affected Counties
All Donor Counties
Non-farm Compensation
40
Fig. 4. Total Harvested Acres and Farm-gate Value (2011 dollars) of All Crops
22
22
3B
illio
ns
of 2
011
Do
llars
(P
PI-
adj
ust
ed)
1,8
00,0
001
,850
,000
1,9
00,0
001
,950
,000
2,0
00,0
00H
arve
sted
Acr
es
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Harvested Acres
Value
Donor Counties
10
11
12
13
Bill
ion
s of
201
1 D
olla
rs (
PP
I-a
dju
sted
)
6,6
00,0
006
,800
,000
7,0
00,0
007
,200
,000
7,4
00,0
00H
arve
sted
Acr
es
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Harvested Acres
Value
Affected Counties - South SJV
41
Fig. 5. Results: Observed and Synthetic Control Values for Farm Employment
25,
000
30,
000
35,
000
40,
000
45,
000
50,
000
Far
m E
mpl
oym
ent
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno - Observed
Synthetic Control + Linear Shift (DD)
Synthetic Control
25,
000
30,
000
35,
000
40,
000
45,
000
50,
000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare - Observed
Synthetic + Linear Shift (DD)
Sythetic Control
5,0
006
,000
7,0
008
,000
9,0
00F
arm
Em
plo
yme
nt
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings - Observed
Synthetic Control
25,
000
30,
000
35,
000
40,
000
45,
000
50,
000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern - Observed
Synthetic Control
42
Fig. 6. Difference Between Observed and Synthetic Value: Farm Employment
-8,0
00
-6,0
00
-4,0
00
-2,0
00
2,0
004
,000
0E
stim
ated
Tre
atm
ent
Eff
ect
(F
arm
Jo
bs)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno
-8,0
00
-6,0
00
-4,0
00
-2,0
00
2,0
004
,000
0
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare-3
,00
0-2
,00
0-1
,00
00
1,0
002
,000
Est
imat
ed T
reat
men
t E
ffe
ct (
Fa
rm J
obs
)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings
-15
,000
-10
,000
-5,0
00
05
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern
43
Fig. 7. Results: Observed and Synthetic Control Values for Farm Compensation
300
,000
400
,000
500
,000
Far
m W
age
Com
pen
satio
n
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno - Observed
Synthetic Control
300
,000
400
,000
500
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare - Observed
Synthetic Control8
0,00
01
00,0
001
20,0
001
40,0
00F
arm
Wa
ge C
omp
ensa
tion
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings - Observed
Synthetic Control
400
,000
500
,000
600
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern - Observed
Synthetic Control
44
Fig. 8. Difference Between Observed and Synthetic Control Values: Farm Compensation
-10
0,00
0-5
0,0
000
50,
000
100
,000
150
,000
Est
imat
ed T
reat
men
t E
ffe
ct (
Fa
rm C
om
pens
atio
n)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno
-10
0,00
0-5
0,0
000
50,
000
100
,000
150
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare-1
00,
000
-50
,000
05
0,00
01
00,0
001
50,0
00E
stim
ated
Tre
atm
ent
Eff
ect
(F
arm
Co
mpe
nsat
ion
)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings
-10
0,00
0-5
0,0
000
50,
000
100
,000
150
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern
45
Fig. 9. Results: Observed and Synthetic Control Values for Non-farm Employment
270
,000
280
,000
290
,000
300
,000
310
,000
Non
-far
m E
mpl
oym
ent
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno - Observed
Synthetic Control
100
,000
105
,000
110
,000
115
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare - Observed
Sythetic Control3
2,00
03
4,00
03
6,00
03
8,00
04
0,00
0N
on-f
arm
Em
plo
yme
nt
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings - Observed
Synthetic Control
Synthetic Control - Linear Shift (DD)
200
,000
210
,000
220
,000
230
,000
240
,000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern - Observed
Synthetic Control
46
Fig. 10. Difference between Observed and Synthetic values: Non-farm Employment
-40
,000
-20
,000
02
0,00
04
0,00
0E
stim
ated
Tre
atm
ent
Eff
ect
(N
on-
farm
Jo
bs)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno
-40
,000
-20
,000
02
0,00
04
0,00
0
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare-2
0,0
000
20,
000
Est
imat
ed T
reat
men
t E
ffe
ct (
No
n-fa
rm J
obs
)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings
-40
,000
-20
,000
02
0,00
04
0,00
0
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern
47
Fig. 11. Results: Observed and Synthetic Control Values for Non-farm Compensation
12,
000,
000
14,
000,
000
16,
000,
000
Non
-far
m W
age
Com
pen
satio
n
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno - Observed
Synthetic Control
4,0
00,0
005
,000
,000
6,0
00,0
00
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare - Observed
Synthetic Control
1,5
00,0
002
,000
,000
2,5
00,0
00N
on-f
arm
Wa
ge C
omp
ensa
tion
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings - Observed
Synthetic Control
10,
000,
000
12,
000,
000
14,
000,
000
16,
000,
000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern - Observed
Synthetic Control
48
Fig. 12. Difference between Observed and Synthetic values: Non-farm Compensation
-2,0
00,
000
-1,0
00,
000
01
,000
,000
2,0
00,0
00E
stim
ated
Tre
atm
ent
Eff
ect
(N
on-
farm
Co
mpe
nsat
ion
)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fresno
-2,0
00,
000
-1,0
00,
000
01
,000
,000
2,0
00,0
00
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Tulare-4
00,
000
-20
0,00
00
200
,000
400
,000
Est
imat
ed T
reat
men
t E
ffe
ct (
No
n-fa
rm C
om
pens
atio
n)
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kings
-2,0
00,
000
-1,0
00,
000
01
,000
,000
2,0
00,0
00
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Kern
49
Data Appendix 1. Employment and compensation data: Employment data are taken from the official estimates of employment by industry and county released by the California Employment Development Department (EDD). These estimates are generated from the Currently Employment Statistics program monthly surveys conducted by the Bureau of Labor Statistics and individual states. Data are benchmarked to payroll tax data from the Quarterly Census of Employment and Wages. Employment data may be downloaded from the EDD website (http://www.labormarketinfo.edd.ca.gov/LMID/Employment_by_Industry_Data.html). Wage income data are taken from the U.S. Bureau of Economic Analysis Table CA06N Compensation of Employees by NAICS Industry”. Industry compensation data can be downloaded from the BEA Regional Economic Accounts webpage (http://www.bea.gov/iTable/index_regional.cfm). Agricultural data are taken from the “Farm Employment” or “Farm Compensation” lines and includes employees and payroll of establishments reporting under NAICS sector 11. Non-agricultural employment data are taken from the “Nonfarm Employment” or “Nonfarm Compensation” lines and include employees and payroll of all other establishments. 2. County Crop Report Data: Crop acreage and value data by county are from county agricultural commissioner’s annual reports. Annual report data from 1980-2011 can be downloaded from USDA-NASS (http://www.nass.usda.gov/Statistics_by_State/California/Publications/AgComm/Detail/index.asp) 3. Water Delivery Data: Annual water delivery data are generated from published reports by the U.S. Bureau of Reclamation (USBR) and the California Department of Water Resources (DWR). Water deliveries for the Central Valley Project are from the 2013 CVP Annual Ratebook Schedule A-14 “Schedule of Historical (1981-2011) & Projected (2012-2030) Irrigation Water Deliveries for Calculation of Individual Contractor Prorated Capital Costs.” Current year versions of this report can be downloaded from USBR (http://www.usbr.gov/mp/cvpwaterrates/ratebooks/). Annual water deliveries for the State Water Project are taken from Appendix B (Table B-5B) of Bulletin 132-12 “Management of the California State Water Project.” This report can be downloaed from DWR (http://www.water.ca.gov/swpao/bulletin_home.cfm). For each project, CVP and SWP, data are reported as the quantity of water delivered each year to each irrigation district contracting with the project. We allocate delivered water to each county in the study area by overlaying maps of all irrigation districts in California onto maps of counties. In cases where irrigation districts span multiple counties, we calculate the percentage of district land area in the two (or more counties) and allocate water deliveries for that district to each county according to the proportion of district land in the county. A full list of irrigation districts is given in the supplemental materials. Deliveries to Sacramento Valley Region control areas consist of deliveries to the following CVP operational units: Sacramento River – Willows, Tehama-Colusa Canal, and Black Butte Unit. Deliveries to San Joaquin Region affected areas consist of deliveries to SWP irrigation districts in Kings and Kern Counties and the following CVP operational units: Buchanan Unit, Cross Valley Canal, Delta-Mendota Canal, Delta-Mendota Pool, Friant Dam, Friant-Kern Canal, Madera Canal, New Melones Unit, and San Luis Canal. 4. Weather Data: Annual precipitation, seasonal cooling degree days, and seasonal heating degree days are from NOAA's National Climatic Data Center (www.ncdc.noaa.gov). County level readings are taken from a weather station within the arable portion of each county. Seasonal cooling and heating degree days are the sum of degree days from April – September. 5. Population and demographic data are from the 2000 U.S. Census.