We develop a dynamic equilibrium model of labor demand with adverse selection. Firms learn the quality of newly hired workers after a period of employment. Adverse selection makes it costly to hire new workers and to release productive workers. As a result, firms hoard labor and under-react to...

An important component of the debate surrounding climate legislation in the United States is its potential impact on labor markets. Theoretically the connection is ambiguous and depends on the sign of cross-elasticity of labor demand with respect to energy prices, which is a priori unknown. This...

Cap and trade systems are emerging as the front-running policy choice to address climate change concerns in many countries. One of the apparent attractions of this approach is the ability to achieve hard limits on emissions over a control period. The cost of achieving this certainty on emission...

In this paper we derive conditions for the conditional covariance matrix to be positive definite in a general vector ARCH model. The conditions can be easily extended to the diagonal vector GARCH model. For the general vector GARCH model, analytical expressions for the conditions in terms of the...