Does order preferencing matter?

This study examines how order preferencing affects the competitiveness and efficiency of laboratory financial markets. We operationalize preferencing by allowing some dealers to execute a portion of the order flow by matching the most favorable quotes available. Increasing the proportion of order how that is preferenced can increase bid-ask spreads, reduce the informational efficiency of prices, and benefit dealers at the expense of liquidity traders. Preferencing has none of these effects, however, when two or more dealers are not receiving preferencing orders. Preferencing may significantly degrade market performance if preferencing arrangements affect all, or virtually all, dealers. (C) 1998 Elsevier Science S.A. All rights reserved.