A policy will be used more heavily in a time and place where its cost is lower. The analyst who treats times and places as identical will overestimate the policy's net benefit, especially for policy intensities greater than exist in his sample. In regression analysis, the problem can be solved...

Randolph Sloof has written a comment on the lobbying-as-signalling model in Rasmusen (1993) in which he points out an equilibrium I missed and criticizes my emphasis on a particular separating equilibrium. In this response, I discuss how to interpret multiple equilibria in games and how to...

Richard Posner suggests several arguments for increasing health care spending on males and reducing it on females in his book, Aging and Old Age . I offer a new formalization of his verbal argument.

This article addresses issues that arise in agency law when agents make contracts on behalf of principals. The main issue is whether the principal should be bound when the agent makes a contract with some third party on his behalf which the principal would immediately wish to disavow. The...

A number of issues in the common law arise when agents make contracts on behalf of principals. Should a principal be bound when his agent makes a contract on his behalf that he would immediately wish to disavow? The tradeoffs resemble those in tort, so the least-cost avoider principle is useful...

One reason to call an activity a vice and suppress it is that it reduces a person’s future happiness more than it increases his present happiness. Gruber and Koszegi (2001) show how a vice tax can increase a person’s welfare in a model of multiple selves with hyperbolic preferences across...

In the reputation model of Klein and Leffler (1981) firms refrain from cutting quality or price because if they did they would forfeit future profits. Something similar can happen even in a static setting. First, if there exist some discerning consumers who can observe quality, firms wish to...

This is an exposition of the BLP method of structural demand estimation using the random-coefficients logit model.