We show that for generic economies, every equilibrium admits Pareto improving monetary policy, even with multiple commodities per state.The main assumption is that asset incompleteness be intermediate, in that household heterogeneity does not exceed the number of assets present and absent.We...

The existence of collateral requirements to the exchange of securities in general reduces the efficiency of competitive equilibria. The general equilibrium analysis is presented in a world where reputation plays no role, and the lender always expects a future payment equal to the minimum between...

In a seminal paper, Ross (Q J Econ 90:75-89, 1976) shows that if security markets are resolving, then there exist (non-redundant) options that generate complete security markets. Complementing his work, Aliprantis and Tourky (2002) show that if security markets are strongly resolving and the...

In this paper, we investigate the existence of multiperiod American options generating dynamically complete markets. We show that if a primitive security separates states at the terminal date, then generically there exist multiperiod American options on that security generating dynamically...

Fixing a risky intertemporal, interagent consumption profile, its quot;social costquot; is the total willingness to pay for smoothing everyone's consumption. It decomposes into a quot;micro costquot; capturing the inefficiency in the distribution of total consumption, risky as it is, and a...

In an exchange economy under uncertainty with two periods, one physical good, and finitely many states of the world, we show that for every (complete or incomplete) market span there exists a sequence of securities such that if they are introduced into markets one by one, the prices of any...

The paper analyzes a two period general equilibrium model with individual risk, aggregate uncertainty and moral hazard. There is a large number of households, each facing two individual states of nature in the second period. These states differ solely in the household's vector of initial...

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...

The stationary sunspot equilibria of a simple OLG economy with heterogeneous agents areconsidered. These equilibria are known to be suboptimal. The focus of the paper is on the efficacy,based on welfare economic considerations and informational requirements, of government policy insuch an...

This paper argues that the introduction of a short-sale constraint in the Arrow-Radner framework invalidates standard definitions of complete and incomplete markets. Two threshold values with familiar properties arise in this constrained set-up. If short sales are not allowed on some security,...