An observer makes a number of observations of an industry producing a homogeneous good.  Each observation consists of the market price, the output of individual firms and perhaps information on each firm's production cost.  We provide various tests (typically, linear programs) with which the...

The single crossing property plays a crucial role in monotone comparative statics (Milgrom and Shannon (1994)), yet in some important applications the property cannot be directly assumed or easily derived.  Difficulties often arise because the property cannot be aggregated: the sum of two...

We consider an observer who makes a finite number of observations of an industry producing a homogeneous good, where each observation consists of the market price and firm specific production quantities.  We develop a revealed preference test (in the form of a linear program) for the hypothesis...

This paper examines under what conditions fiscal policy in the form of government spending should contribute to macroeconomic stabilisation.  To this end optimal fiscal targeting rules minimising the microfounded social loss are examined in the following settings.  Firstly, for the benchmark...

We consider optimal monetary and fiscal policies in a New Keynesian model of a small open economy with sticky prices and wages.  In this benchmark setting monetary policy is all we need - analytical results demonstrate that variations in government spending should play no role in the...

For economies in which goods are available in several (discrete) units, this paper identifies two notions of substitutes. The weaker notion guarantees monotonicity of tatonnement processses and convergence of clock auctions to a pseudo-equilibrium, but only the stronger notion, which treats each...

The paper proves the existence of equilibrium in nonrenewable resource markets when extraction costs are non-convex and resource storage is possible.  Inventories flatten the consumption path and eliminate price jumps at the end of the extraction period.  Market equilibrium becomes then...

Individual behaviors such as smoking, fashion, and the adoption of new products is influenced by taking account of others' actions in one's decisions.  We study social influence in a heterogeneous population and analyze the long-run behavior of the dynamics.  We distinguish between cases in...

Mertens and Parthasarathy (1987) proved the existence of sub-game perfect equilibria in discounted stochastic games.  Their method involved new techniques in dynamic programming, which were presented in a very general framework, with no expense spared in highlighting versatility and scope. ...

This paper proposes a measure of financial fragility that is based on economic welfare in a general equilibrium model calibrated against UK data. The model comprises a household sector, three active heterogeneous banks, a central bank/regulator, incomplete markets, and endogenous default. We...