Instrumental Variables (IV) methods identify internally valid causal effects for individuals whose treatment status is manipulable by the instrument at hand. Inference for other populations inevitably requires some sort of homogeneity assumption. I develop a simple theoretical framework that...

In this paper, we develop a search-based model of asset trading. We assume that investors differ in their horizons, and can invest in two identical assets. The asset markets are partially segmented: investors can search in only one market, but can decide which one. We show that there exist a...

In this paper, I study the welfare properties of growth models with endogenous innovation, knowledge externalities, and monopoly pricing of new goods. Since useful policy prescriptions cannot be inferred from a balanced growth analysis, welfare is analyzed for transition paths. I provide a...

This paper studies an international tax policy design problem by employing a two-country dynamic general equilibrium model with incomplete asset markets. We investigate the possibility of welfare-improving active tax policies, in particular capital and labor income tax, under the non-cooperative...

In this paper, we develop a search-based model of asset trading. We assume that investors differ in their horizons, and can invest in two identical assets. The asset markets are partially segmented: investors can search in only one market, but can decide which one. We show that there exist a...

One result of the deregulation of utilities in New Zealand has been the bypass of existing networks. We investigate two cases of bypass in the distribution of natural gas, and compare the welfare properties of regulation vs.\ the `laissez-faire' equilibrium. We demonstrate that installing a...

This paper proposes a simple framework for analyzing a continuum of monetary policy rules characterized by differing degrees of credibility, in which commitment and discretion become special cases of what we call quasi commitment. The monetary policy authority is assumed to formulate optimal...