Using the restrictions implied by the heteroskedasticity of stock returns, we identify four factors in the U.S. industry returns. The first correlates highly with the market portfolio; the second is a portfolio of stocks that produce investment goods minus stocks that produce consumption goods;...

This note provides a simple exposition of what IV can and cannot estimate in a model with a binary treatment variable and heterogeneous treatment effects. It shows how linear IV is a misspecification of functional form and the reason why linear IV estimates for this model will always depend on...

Assortative Matching between workers and firms provides evidence of the complementarities or substitutes in production. The presence of complementarities is important for policies that aim to achieve the optimal allocation of resources, for example unemployment insurance. We argue that using...

Bajari, Benkard and Levin (2007) propose an estimation methodology for a broad class of dynamic optimization problems. To carry out their procedure, one needs to select a set of alternative policy functions and compare the implied expected payoffs with that from the data. We show that this can...

The standard New Keynesian model suffers from the so-called .macro-micro pricing conflict: in order to match the dynamics of inflation implied by macroeconomic data, the model needs to assume an average duration of price contracts which is much longer than what is observed in micro data. Here I...

We examine the allocation of hours of work across industrial sectors in OECD countries. We find large disparities across three sector groups, one that produces goods without home substitutes, and two others that have home substitutes but are treated differently by welfare policy. We attribute...

The labor search and matching model plays a growing role in macroeconomic analysis. This paper provides a critical, selective survey of the literature. Four fundamental questions are explored: how are unemployment, job vacancies, and employment determined as equilibrium phenomena? What...