This paper argues that the introduction of a short-sale constraint in the Arrow-Radner frameworkinvalidates standard definitions of complete and incomplete markets. In this constrained set-up,two threshold values with familiar properties arise.The case of a zero short-sale bound set on some...

I study the welfare implications of size-dependent firm regulation policies (SDPs) in the presence of entrepreneurial risks. Although SDP has been considered a source of misallocation, I show that, once entrepreneurial risks are taken into account, SDP can improve efficiency. Quantitatively, I...

Although almost nonexistent 15 years ago, there are now numerous papers that analyze models with both aggregate uncertainty and a large number—typically a continuum—of heterogeneous agents. These models make it possible to study whether macroeconomic fluctuations affect different agents...

While it is common knowledge that portfolio separation in a continuous-time lognormal market is due to the basic properties of the Gaussian distribution, the usual textbook exposition relies on dynamic programming and thus Itô stochastic calculus and the appropriate regularity conditions. This...

In this paper we study the effects of financial integration on risk-sharing. Conventional macroeconomic theory suggests that the integration of financial markets improves welfare. In contrast to the literature we assume that households have heterogeneous beliefs. Because of the differences in...

This paper is a quantitative, equilibrium study of the insurance role of severance pay when workers face displacement risk and markets are incomplete. A key feature of our model is that, in line with an established empirical literature, job displacement entails a persistent fall in earnings upon...

When individuals' labor and capital income are subject to uninsurable idiosyncratic risks, should capital and labor be taxed, and if so, how? In a two-period general equilibrium model with production, we derive a decomposition formula of the welfare effects of these taxes into insurance and...

This paper formally compares the fit of various versions of the incomplete markets model with aggregate uncertainty, relying on a simple Bayesian empirical framework. The models differ in the degree of households' heterogeneity, with a focus on the role of preferences. For every specification,...

In this paper, we examine an exchange economy with a financial market composed of three assets: a share of a stock, an European call option written on the stock, and a riskless bond. The financial market is assumed to be incomplete and the option is not a redundant asset. In such a case the...

We provide a geometric test of whether a general equilibrium incomplete markets (GEI) economy has Hart points---points at which the rank of the securities payoff matrix drops. Condition (H) says that, at each nonterminal node, there is an affine set (of appropriate dimension) that intersects all...