variation. Fortunately, reliable micro data sets like the one obtained in this
paper to test our propositions are becoming increasingly available for longer
time periods.
As stressed in this paper, our approach to the IIA problem is compliant
with the Random Profit Maximization framework. Estimating a Poisson re-
gression model with random effects is equivalent to estimating a particular
case of the mixed logit model. Equivalently, the results of a Poisson re-
gression with fixed-effects are the same as those obtained from a CLM with
an alternative specific constant. Hence, this paper also shows that there is
a theoretical foundation for a recent branch of the location literature that
relies on the Poisson model and its extensions.
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