In a second best environment, the optimal policy choice sometimes follows the first best rules. This note lays down the information structure and separability assumptions under which this property holds in a variety of setups.

The theoretical effects of labour regulations such as employment protection legislation (EPL) on innovation is ambiguous, and empirical evidence has thus far been inconclusive. EPL increases job security and the greater enforceability of job contracts may increase worker investment in innovative...

This paper reviews some of the econometric methods that have been used in the economics of education. The focus is on understanding how the assumptions made to justify and implement such methods relate to the underlying economic model and the interpretation of the results. We start by...

Heterogeneity is likely to be an important determinant of the shape of optimal tax schemes. This article addresses the issue in a model à la Mirrlees with a continuum of agents. The agents differ in their productivities and opportunity costs of work, but their labor supplies depend only on a...

Much of the literature on externalities has considered taxes and direct regulation as alternative policy instruments. Both instruments may in practice be imperfect, reflecting informational deficiencies and other limitations. We analyse the use of taxes and regulation in combination, to control...

We study optimal taxation in the general extensive model: the only decision of the participants in the economy is to choose between working (full time) or staying inactive. People differ in their productivities and in other features which determine their work opportunity costs. The qualitative...

This paper develops a tractable, heterogeneous agents general equilibrium model where individuals have different endowments of the factors that complement the schooling process. The paper explores the relationship between inequality of opportunities, inequality of outcomes, and efficiency in...

In the famous debate between Keynes and Ohlin on the transfer problem, the interaction between non-traded goods and unemployment complicates the analysis considerably. We analyze these issues using four different models to conclude that Keynes's concern regarding the large burden imposed on...

Making use of restrictions imposed by equilibrium, theoretical progress has been made on the nonparametric and semiparametric estimation and identification of scalar additive hedonic models (Ekeland, Heckman, and Nesheim, 2002) and scalar nonadditive hedonic models (Heckman, Matzkin, and...