We develop a model of financially constrained arbitrage, and use it to study the dynamics of arbitrage capital, liquidity, and asset prices. Arbitrageurs exploit price discrepancies between assets traded in segmented markets, and in doing so provide liquidity to investors. A collateral...

This paper formalizes the idea that more hedging instruments may destabilize markets when traders are heterogeneous and adapt their behavior according to experience based reinforcement learning. We investigate three different economic settings, a simple mean-variance asset pricing model, a...

Traditional finance is built on the rationality paradigm. This chapter discusses simple models from an alternative approach in which financial markets are viewed as complex evolutionary systems. Agents are boundedly rational and base their investment decisions upon market forecasting heuristics....

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

We consider a complete financial market with primitive assets and derivatives on these primitive assets. Nevertheless, the derivative assets are non-redundant in the market, in the sense that the market is complete, only with their existence. In such a framework, we derive an equilibrium...

We evaluate the asset pricing implications of a class of models in which risk sharing is imperfect because of limited enforcement of intertemporal contracts. Lustig (2004) has shown that in such a model the asset pricing kernel can be written as a simple function of the aggregate consumption...

This essay reviews the family of models that seek to provide aggregate risk based explanations for the empirically observed equity premium. Theories based on non-expected utility preference structures, limited financial market participation, model uncertainty and the small probability of...

We develop a method that allows one to compute incomplete-market equilibria routinely for Markovian equilibria (when they exist). The main difficulty to be overcome arises from the set of state variables. There are, of course, exogenous state variables driving the economy but, in an incomplete...

We develop a dynamic model of liquidity provision, in which hedgers can trade multiple risky assets with arbitrageurs. We compute the equilibrium in closed form when arbitrageurs' utility over consumption is logarithmic or risk-neutral with a non-negativity constraint. Liquidity is increasing in...

In this paper we survey the theoretical and empirical literature on market liquidity. We organize both literatures around three basic questions: (a) how to measure illiquidity, (b) how illiquidity relates to underlying market imperfections and other asset characteristics, and (c) how illiquidity...