A Comparison of Stock Market Mechanism

I analyze a static, noisy rational expectations equilibrium model where traders exchange vectors of assets accessing multi-dimensional information under two alternative market structures. In the first (the unrestricted system), informed speculators condition their demands for each asset on all equilibrium prices and market makers set prices observing all order flows; in the second (the restricted system), speculators are restricted to condition their demand on the price of the asset they want to trade and market makers only observe the order flow of the asset they price. I show that informed traders' incentives to collect and exploit multi-dimensional private information depend on the number of prices they can condition upon when submitting their demand schedules, and on the specific price formation process one considers. Building on this insight, I then give conditions under which the restricted system is more efficient than the unrestricted system.