Equilibrium and Welfare in Markets with Financially Constrained Arbitrageurs

Working Paper: CEPR ID: DP3049

Authors: Denis Gromb; Dimitri Vayanos

Abstract: We propose a multi-period model in which competitive arbitrageurs exploit discrepancies between the prices of two identical risky assets, traded in segmented markets. Arbitrageurs need to collateralize separately their positions in each asset, and this implies a financial constraint limiting positions as a function of wealth. We derive an equilibrium and study its welfare properties. Allowing arbitrageurs to trade makes all investors better off. Arbitrageurs' positions may not be Pareto optimal, however, in the sense that a change in these positions may make all investors better off. We characterize conditions under which arbitrageurs take excessive or too little risk.

Keywords: arbitrage; borrowing constraints; collateral; liquidity; welfare

JEL Codes: D62; G12; G18; G23; G30


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
Collateral constraints (D10)Arbitrageurs' positions in risky assets (G19)
Arbitrageurs' trading (G19)Market welfare (D69)
Financial constraints (D10)Risk-taking behaviors (D91)
Risk-taking behaviors (D91)Market stability and welfare (D53)
Wealth levels (D31)Arbitrageurs' positions in risky assets (G19)

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