In this paper we use global analysis to study the welfare properties of general equilibrium economies with incomplete markets (GEI). Our main result is to show that constrained Pareto optimal equilibria are contained in a linear submanifold of the equilibrium set. This result is explicitly...

It is known that the incompleteness of asset markets causes inefficiency in almost every equilibrium. Yet unexplored is the ”size” of this inefficiency. The size of a Pareto improvement is the total willingness to pay for it, out of current consumption. Inefficiency is the maximum size of...

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...

A classic characterization of competitive equilibria views them as feasible allocations maximizing a weighted sum of utilities. It has been applied to establish fundamental properties of the equilibrium notion, such as existence, determinacy, and computability. However, it fails for economies...

This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante...

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...

When asset markets are incomplete there are almost always many Pareto improving policy interventions. Remarkably, these interventions do not involve adding any new markets. Focusing on tax policy, I create a framework for proving the existence of Pareto improving taxes, for computing them, and...

In this paper, we provide a characterization of interim inefficiency in stochastic economies ofoverlapping generations under possibly sequentially incomplete markets. With respect to the established body of results in the literature, we remove the hypothesis of two-period horizons,by considering...

A classic characterization of competitive equilibria views them as feasible allocations maximizing a weighted sum of utilities. It has been applied to establish fundamental properties of the equilibrium notion, such as existence, determinacy, and computability. However, it fails for economies...