Asset pricing in created markets.
by Newell, Richard G.^Papps, Kerry L.^Sanchirico, James N.
Improvements in profits through cost reductions can also occur as a
result of improvements in fish stock abundance, and associated increases
in the catch-per-unit-effort. We represent this feature using a dummy
variable, a, that indicates whether each stock faced significant
reductions upon implementation of the ITQ program. (13) We expect that
fisheries plagued by excess capacity and overfishing prior to the
implementation of the ITQ system that also faced significant reductions
in allowable catch at the outset of the ITQ program would experience
greater increases in profitability through stock rebuilding and cost
rationalization than fish stocks without a high degree of overfishing,
everything else being equal. Thus, we would expect the coefficient on a
to be positive, indicating that for a given lease price, the asset price
will be higher for stocks with fish stock rebuilding plans in place.
Over time, however, the gains from such improvements should be
realized, implying that future gains will be lower. We capture this
effect by interacting a with a time trend, hypothesizing that over time
the lease price will rise as stocks improve, and the effect on the asset
price of additional future gains will diminish. Under these conditions,
we would expect the coefficient on the interaction of a and t to be
negative.
Estimation Approach
Time-Series Properties of Data
Before considering estimation of equation (6), it is essential to
determine the time series properties of the asset and lease price
series. If either one or both of the series are nonstationary, then
standard regression techniques will be susceptible to the problem of
spurious regression.
While testing for unit roots in panels is a relatively new
enterprise, there are several tests available to researchers (see
Banjeree [1999] for more information on the tests). We employ three
tests, all of which can be thought of as panel data extensions or pooled
versions of the Dickey-Fuller test (or Augmented Dickey-Fuller test when
lags are included). Full details are given in the supplemental appendix
(Newell, Papps, and Sanchirico 2007). In all three cases, we reject the
hypothesis of a unit root in both the asset and lease price series at
the 1% level. The same result holds when the tests are repeated using
species-level (rather than stock-level) data. The agreement in the time
series properties of the asset and lease prices satisfies, at least at
the panel level, a necessary condition of the present-value model (Falk
1991). (14)
We also test for the possibility of nonstationarity in the
quarterly New Zealand real interest rate for thirty-day Treasury bills
and the quarterly species-level export price, which is used as an
instrument in the econometric analysis for contemporary lease prices. In
both cases, we reject the null hypothesis of a unit root. Therefore, the
time series variables in the regressions to follow are all stationary,
allowing us to draw inferences from the use of standard panel data
techniques with variables in levels.
Panel Estimation Techniques
Because lease prices and asset prices are determined simultaneously
in the ITQ market each period, it is likely that estimation of equation
(6) suffers from simultaneity bias. Statistical tests for endogeneity of
the lease price verify this concern. (15) We therefore use instrumental
variables estimation throughout, instrumenting for the log lease price
using the logged contemporaneous export price of fish and all other
regressors, including stock fixed effects. The price of fish is an
excellent instrument as it is a significant determinant of profits from
fishing, it is highly correlated with quota lease prices ([rho] = 0.77),
and it is clearly exogenous. (16) Our estimation approach follows
Balestra and Varadharajan-Krishnakumar (1987), employing a two-stage
least squares generalization of the standard panel data estimators to
correct for endogeneity. See Baltagi (2001) for an introduction to panel
data models with endogenous explanatory variables.
Our first specification models the data for all stocks in a pooled
fashion. This approach is appropriate if there are no unobserved
stock-specific effects. In contrast, our second specification performs
the within estimator, which is equivalent to a regression with a full
set of stock-specific fixed effects. While the within estimator is
consistent, it is not as efficient as other estimators (e.g., random
effects) if the unobserved stock-specific effect is uncorrelated with
the observed regressors. In addition, with the fixed effects approach it
is not possible to recover coefficients on any of the time-invariant
regressors, namely the export price growth rate, mortality rate, and
recovering stock dummy.
Our third specification performs the between estimator, which is a
regression of stock-specific averages over time. As such, this
specification cannot identify coefficients on stock-invariant
regressors, such as the interest rate. Finally, our fourth specification
treats the stock-specific term, [v.sub.ij] as a random effect. This
model is more efficient than within estimation when none of the
regressors is correlated with the stock-specific effect, however, it is
inconsistent when the opposite is true. This assumption of no
correlation is typically assessed using a Hausman test. The random
effects estimator has the advantage of controlling for stock-specific
effects while at the same time allowing for estimation of time-invariant
explanatory variables, which are of central interest to this article.
Beyond the fixed or random effect, we assume that the remaining error is
homoskedastic. This is supported by panel tests of both
heteroskedasticity (Pagan and Hall 1983) and autocorrelation (Wooldridge
2002), neither of which rejected a homoskedastic error structure.
Estimation Results
In table 3, we report the results of estimating equation (6) using
the fishing quota asset and lease price data described above. Due to
some observations having missing values for one or more of the
variables, 4,120 observations were available for the four models that
are reported. All the four specifications show a high degree of
explanatory power, with [R.sup.2] values of 0.77 or above. Overall, the
results are consistent with economic predictions about the parameters.
The estimated coefficients generally have the expected signs and
reasonable magnitudes and are stable across the different
specifications.
Regarding the appropriateness of the different specifications, we
find that a joint F-test of the fixed effects is highly significant,
thereby opening up the standard errors and consistency of the pooled
model to misspecification. On the other hand, a Hausman test comparing
the fixed effects and random effects estimators clearly indicates that
the random effects model is appropriate (i.e., the assumption of no
correlation between the regressors and the random effect is not
rejected). Hence, the random effects estimates are consistent and more
efficient than the fixed effects (or between) estimates. Indeed, the
stability of the coefficients across these specifications illustrates
the consistency of the parameter estimates in the random effects model.
The four specifications reported in table 3 feature an estimated
coefficient on log lease price of between 0.76 and 0.86. We find that
the random-effects estimate for the lease price coefficient lies between
the within estimate (model ii) and the between estimate (model iii), as
one would expect given that the random effects estimator is an efficient
weighted average of the within and between estimators (when its
assumptions are upheld). These results suggest that changes in lease
prices are reflected very closely in changes in the contemporaneous
quota asset prices. However, the point estimates are somewhat lower than
the expected coefficient of 1 based on the simple present-value model
given above, or based on the simple univariate relationship depicted in
figure 2. (17)
It is not clear how much this lower-than-expected estimated
coefficient casts doubt on the simple present value model represented by
equation (6), although it suggests that it may not hold exactly. One
possibility is an errors-in-variables problem, with the standard
implication that the resulting coefficient is biased toward zero.
Another possibility is that the various controls included in the model
(e.g., year effects) are simply reducing the amount of variation in
lease prices available for estimating that coefficient. This conjecture
is supported by a simple random or fixed effects regression of log quota
asset prices on (instrumented) log quota lease prices, with no other
controls. In these simple models the coefficient on the log lease price
is 0.98 in the case of the random effects model and 1.04 in the fixed
effects model, with neither of these estimates being statistically
different from 1.
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