The arbitrage argument extends to the case of many risk assets: the equilibrium leverage ratio will vary with the riskiness of the asset backing up the loan and variations in leverage will then substitute for variations in the interest rate. However, it can readily be shown along the lines of [Vernon L.] Smith that competition in leverage terms would be insufficient to correct the inefficient allocation of claims produced by the market when the interest rate is fixed.4

ABSTRACT This paper models an individual's trading decision, given: (1) his/her demand function to hold shares of an asset, (2) his/her expectation on what the market clearing price will be, and (3) the design of the market which determines how orders will be translated into trades. The particular market design we consider is the batched trading (periodic call) regime. Assuming investors are distributed according to their propensities to hold shares, we model the aggregation of orders to obtain market clearing values of price and volume and to show the way in which, with trading friction, these solutions differ from Pareto efficient values. The importance of this analysis for various issues concerning market design is noted.

By considering investor order placement strategy, this paper demonstrates that transaction costs cause bid-ask spreads to be an equilibrium property of asset markets. With transaction costs, the probability of a limit order executing does not go to unity as the order is placed infinitesimally close to a counterpart market quote; thus, with certainty of execution at the counterpart market quote, a "gravitational pull" is generated that keeps counterpart quotes from being placed infinitesimally close to each other. An equilibrium spread is defined and its size linked to market thinness; implications are noted for the design of a trading system.

Kalman J. Cohen, Steven F. Maier, Robert A. Schwartz, David K. Whitcomb, Market Makers and the Market Spread: A Review of Recent Literature, The Journal of Financial and Quantitative Analysis, Vol. 14, No. 4, Proceedings of 14th Annual Conference of the Western Finance Association, June 21-23, 1979 (Nov., 1979), pp. 813-814+816-835