The Response to Incentives and Contractual Efficiency: Evidence from a Field Experiment

We investigate the efficiency of piece-rate contracts using data from a field experiment, conducted within a tree-planting firm. During the experiment, the piece rate paid to planters was exogenously increased. Regression methods yield an estimate of the elasticity of output with respect to changes in the piece rate of 0.39. Regression methods are limited in their ability to predict the performance of alternative contracts. Therefore, we apply structural methods to interpret the experimental data. Our structural estimate of the elasticity is 0.37, very close to the regression estimate. Importantly, our structural model is identified without imposing profit maximization. This allows us to evaluate the optimality of the observed contract. We simply measure the profit distance between the observed contract and the profit-maximizing contract, evaluated at the structural parameter estimates. We estimate this distance to be negligible, suggesting that the observed contract closely approximates the expected-profit maximizing contract under asymmetric information. Under complete information, expected profits would increased by approximately fourteen percent, holding expected utility constant.