Knowledge that Transforms

The authors analyze the evolution of duopolists' prices and market shares in an infinite-period market with consumer switching costs in which in every period new consumers arrive and a fraction of old consumers leaves. They show prices (and profits) are higher than without switching costs and that this result does not depend importantly on their specific assumptions. The authors show switching costs make the market more attractive to a new entrant, even though an entrant must overcome the disadvantage that a large fraction of the market is already committed to the incumbent's product. They also examine the effects of market growth. Copyright 1992 by The Econometric Society.

A dynamic stochastic model for a competitive industry is developed in which entry, exit, and the growth of firms' output and employment is determined. The paper extends long-run industry equilibrium theory to account for entry, exit, and heterogeneity in the size and growth rate of firms. Conditions under which there is entry and exit in the long run are developed. Cross sectional implications and distributions of profits and value of firms are derived. Comparative statics on the equilibrium size distribution and turnover rates are analyzed. Copyright 1992 by The Econometric Society.

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Quotas are the predominant means of protection in developed countries, with quota rents commonly shared between exporter and importer. This paper derives shadow prices appropriate to evaluating trade reform under these circumstances and provides a number of useful sufficient conditions for welfare-improving "piecemeal" reform. In doing so, the authors apply the distorted (quantity-constrained) expenditure function and use implicit separability to derive more powerful results than have previously been available.

This paper proposes a new test statistic to deter the presence of heteroskedasticity. The proposed test does not require a parametric specification of the mean regression function in the first stage regression. The regression function is estimated nonparametrically by the kernel estimation method. The nonparametric residual is estimated and used as a proxy for the random disturbance term. This nonparametric residual is robust to regression function misspecification. Asymptotic normality is established using extensions of classical U-statistic theorems. The test statistic is computed using the nonparametric quantities, but the resulting inference has a standard chi-square distribution. Copyright 1992 by The Econometric Society.

Although their goal is to separate a decision maker's underlying beliefs (their subjective probabilities of events) from their preferences (their attitudes toward risk), classic choice-theoretic derivations of subjective probability all rely upon some form of the Marschak-Samuelson "Independence Axiom" or the Savage "Sure-Thing Principle, " which is equivalent to requiring that the decision maker's preferences over lotteries conform to the expected utility hypothesis. This paper presents a choice-theoretic derivation of subjective probability which satisfies the axioms of classical probability theory, but which neither assumes nor implies that the decision maker's preferences over lotteries necessarily conform to the expected utility hypothesis.

Robert E. Cumby, John Huizinga, Testing the Autocorrelation Structure of Disturbances in Ordinary Least Squares and Instrumental Variables Regressions, Econometrica, Vol. 60, No. 1 (Jan., 1992), pp. 185-195

This paper considers estimation of truncated.and censored regression models with fixed effects. Up until now, no estimator has been shown to be consistent as the cross-section dimension increases with the time dimension fixed. Trimmed least absolute deviations and trimmed least squares estimators are proposed for the case where the panel is of length two, and it is proven that they are consistent and asymptotically normal. It is not necessary to maintain parametric assumptions on the error terms to obtain this result. A small scale Monte Carlo study demonstrates that these estimators can perform well in small samples. Copyright 1992 by The Econometric Society.

A principal has private information that directly affects her agent's payoff (i.e., "common values" obtains). The authors analyze their relationship as a three-stage game: (1) the principal proposes a contract; (2) the agent accepts or rejects; and (3) the contract is executed. They show that the equilibrium outcomes are the allocations that weakly Pareto dominate the allocation maximizing the payoff of each "type" of the principal within the class of incentive-compatible allocations ensuring the agent his reservation utility irrespective of his beliefs about the principal's type. The authors also characterize the equilibria that are immune to renegotiation. Copyright 1992 by The Econometric Society.