In most of the states, rebate amounts were functions of either
adjusted gross income or taxable income in previous years. Thus,
imputing rebate amounts requires a measure of income earned for those
individuals who lived in that state one or two years prior to the rebate
year. Unfortunately, the Consumer Expenditure Survey does not contain
data on income or location that far back, so some assumptions must be
made in order to make this imputation. I first assume that all
individuals who report living in one of the four states in the interview
year have not moved in the past two years, and are, thus, eligible to
receive a rebate check. Second, since the CEX contains data on income in
the previous 12 months as of the second and fifth interviews, I create a
measure of income in the year relevant to the rebate calculation by
taking the earliest report of income and discounting it using the CPI-U
price index. (18) The Minnesota and Oregon rebates were based on the
amount of taxable income in a previous year. To translate the income
variables reported in the CEX to taxable income, I assume that all
married couples file jointly, all single individuals file single, and
all individuals claim the standard deduction and exemptions available in
that particular state and year. In Wisconsin, the rebate amounts were
based on adjusted gross income, so I assume that respondents in the CEX
reported their AGI as their income before taxes. Finally, using the
state rebate formulae, rebate amounts were calculated for each household
from these states.
In Connecticut, on the other hand, rebates in 1998 were distributed
to anyone who had filed an income tax return or had paid property taxes
on a residence or motor vehicle, and the amount of the rebate was fixed
subject only to the requirement that the rebate check could not exceed
the individuals' tax liability after taking the property tax credit
in the previous year. To impute these rebate amounts, I use data from
the respondent's base interview on home and car ownership, and
assume that only households that reported ownership of either of these
received a rebate check. In addition, due to the lack of information on
tax liability in the previous year, I assume the maximum amount was
received. (19)
Since some consumer units may contain more than one tax unit, I use
the CEX member--characteristics files to calculate rebate amounts
separately for the head (and wife if applicable) of the consumer unit,
and for all other individuals residing in the consumer unit. (20) I then
sum these amounts within the consumer unit to arrive at a total amount
of imputed rebates received.
The benefit of using these imputed rebate amounts in the
regressions is that they account for the different rebate amounts that
households received, both across and within states. However, although
these imputations should work well for those individuals with steady
income and whose geographic location is steady, they will probably
perform poorly for those observations with highly variable income or
those who have moved.
Although the CEX cannot be used to gauge the appropriateness of
these assumptions, other datasets can shed some light on this issue. In
Table 3, using data from the Panel Study of Income Dynamics (PSID), I
examine the extent to which residents of the states and years under
analysis exhibited steady state of residence and income amounts. (21)
As can be seen in the left panel of this table, among those who
were in one of the rebate--receiving states in a rebate-receiving year,
over 90 percent of respondents were in that state in the prior year on
which the rebate is based. In the right panel, the correlation between
discounted current income and income in the year on which the rebate was
based is also generally high, exceeding 80 percent in all but three of
the rebate state--year pairs.
Thus, it appears that the assumptions made in the calculation of
the rebate amounts are not bad approximations to reality. Nevertheless,
if they are wrong, then the rebate amounts may suffer from nonclassical
measurement error, with an unknown bias resulting. To provide a check on
the robustness of the results using imputed rebate amounts, I also
perform the regressions using dummy variables for rebate receipt as
regressors. This variable likely suffers from less measurement error, as
the imputation of this variable depends primarily on the location of the
respondent. (22) However, using dummy variables to characterize rebate
receipt has a downside in that rebate checks differed greatly in amount
both across states and within states. (23) As a result, treating such
disparate policies identically in the estimation equations could result
in magnified standard errors on the rebate dummy variable coefficients.
Finally, to examine further who responds to the receipt of rebate
checks, I run specifications that include only those who might be credit
constrained. To do this, I include individuals with low asset/ income
ratios by dividing a respondent's earliest observation of the total
value of the balance in their savings and checking accounts, U.S.
savings bonds, and the value of all stocks, bonds, mutual funds, and
other securities by their earliest report of income, and cut the sample
according to the magnitude of this variable. I also run regression
separately by the marital status of the head of the consumer unit.
Summary statistics are presented in Table 4. The base sample of
individuals from the four rebate-receiving states includes 6,316
respondent-quarter pairs. On average, the quarterly change in all
measures of expenditures is approximately zero, as one would expect.
However, there is substantial variation around this mean. A rebate check
was received in 8.2 percent of the observations, and the mean rebate
check amount among those who received one was $372. In Table 5, the
characteristics of these rebates are presented by state and year of
receipt. Overall, the sample contains 518 households that received a
rebate check in some quarter.
Estimation Method
If the rebate policies implemented in these four states induced
their residents to increase their expenditures in the quarter in which
the rebate check was received, then their expenditures should increase
more (or decrease less) relative to the previous quarter than those of
similar individuals in states that did not receive the rebate check.
One way to identify the effects of the rebate program, then, would
be to compare the individuals in the four rebate-receiving states with
individuals in other states. In essence, one could do a difference in
differences estimation, letting individuals in the four states be the
treatment group and individuals in other states be the control group. In
order for this to be valid, however, one would have to make the
assumption that, absent the tax rebate, the change in consumption in the
rebate-receiving states would have been the same as that in the
non-receiving states. This assumption would be problematic if the reason
that these states issued rebate checks was that they had received some
positive income shock, which would presumably also affect consumption
directly. Since this story seems plausible, individuals in other states
might not be a good control group for those in rebate-receiving states.
Instead of this identification strategy, I exploit variation in the
timing of rebates across rebate-receiving states to identify the effects
of these rebates on expenditures. Essentially, for a rebate in a given
state-quarter, individuals in the other states that at some point
received a rebate, but did not receive one in that particular quarter,
act as a control group for those who did receive the rebate in that
quarter. For example, a rebate was distributed in Oregon during November
of 1995. In the estimation, then, respondents from quarters containing
November of 1995 living in Connecticut, Minnesota, or Wisconsin (who did
not receive a rebate in that quarter) serve as a control group for those
in Oregon (who did receive a rebate).
In order for this identification strategy to be valid, I have to
assume that the change in consumption in a rebate-receiving
state-quarter, absent the rebate, would have been the same as in the
other rebate receiving states. This assumption seems much more plausible
than assuming that consumption would be the same as in the
non-'rebate states, but might still be a problem if rebates were
passed quickly in response to positive shocks in income. In this case,
the timing of the rebate would be correlated with the timing of the
positive income shock, and so it may be the income shock to which the
individuals are responding instead of the rebate. However, legislative
delays diminish this concern, since the initial discussions of tax
rebates usually occurred several months before any law was passed or any
check was sent out. Nevertheless, as a robustness check, I also perform
regressions using individuals in all other states as controls for the
individuals in rebate-receiving states.
In the base specification, similar to Souleles (1999, 2002) and
Johnson et al. (2004), I estimate equations of the form
[1] [[DELTA]C.sub.i,t] = [[alpha].sub.0] +
[[alpha].sub.r][rebate.sub.ist] + [summation over
(t)][[alpha].sub.t][d.sub.t] + [summation
over(s)][[alpha].sub.s][d.sub.s] + [a.sub.z][Z.sub.i] +
[[epsilon].sub.ist],
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