A SPECIALIST'S QUOTED DEPTH AS A STRATEGIC CHOICE VARIABLE: AN APPLICATION TO SPREAD DECOMPOSITION MODELS

Although there is a sizable literature demonstrating that liquidity and transaction costs are multidimensional, researchers continue to estimate adverse-selection costs using only prices. We present a model of a profit-maximizing specialist who posts prices and depths. The model is simulated to measure changes in the adverse-selection component of the spread that result under different levels of informed trading. We find that spread decompositions fail to capture the full extent of adverse-selection risk when specialists choose depth. We recommend that researchers use adverse-selection measures that account for depth as well as spread to mitigate this problem. 2006 The Southern Finance Association and the Southwestern Finance Association.