This paper develops a model where firms make state-dependent decisions on both pricing and acquisition of information. It is shown that when information is not perfect, menu costs combined with the aggregate price level serving as an endogenous public signal generate rigidity in price setting...

This paper assumes that workers can move from a market with high unemployment to one with low unemployment at a cost. In principle. equilibrium mobility can be greater or less than the social optimum. For most plausible parameter values. however. mobility is too low. Intuitively. mobility has a...

Climate change is a global "free rider" problem because significant abatement of greenhouse gases is an expensive public good requiring international cooperation to apportion compliance among states. But it is also a global "free driver" problem because geoengineering the stratosphere with...

This paper develops a simple model of a polluting industry and an innovating firm. The polluting industry is faced with regulation and costly abatement. Regulation may be taxes or marketable permits. The innovating firm invests in R&D and develops technologies which reduce the cost of pollution...