The measure of technical efficiency (TE5) of shrimp boat i on trip t is expressed as the ratio of actual output over the maximum feasible output (shrimp landed by a fully efficient boat Uit¼0) given the production technology employed (Battese and Coelli, 1998). It shows how far a particular boat i on trip t is from the technically efficient frontier. A ratio of 1 in Equation 3 would indicate that actual output was equal to the frontier output. Stochastic frontier models may differ in their specification of the inefficiency term Uit. The three basic models estimated here assume different distribution for Uit, namely: exponential, half-normal and the truncatednormal with truncation point at zero.