Optimal audit policies with correlated types

Summary.

We propose a version of Townsend’s [17] model of costly audits where the agents’ types are correlated. Audits are used because agents have a limited ability to bear risk so that the Full Surplus Extraction (FSE) scheme á la Crémer and McLean [5,6] and McAfee and Reny [13] are suboptimal. It is shown that Townsend’s result is a special case of our model when agent types are uncorrelated. The performed numerical simulation of the model using two agents and two types offers interesting insights into what we call the Townsend Ridge. Indeed, the optimal contract which specifies wages to be paid and the audit strategy are remarkably different from one side of the ridge to the next. The observed discontinuity at the ridge reflects a discreet change from a single to a dual audit policy.