Testing for relative performance between seasons in a fishery.

The relative performance between seasons in a fishery is tested empirically. In particular, the importance ora stochastic environment—what may be denoted as fishing luck in a fishery—is established by applying DickeyFuller unit-root tests for the efficiency scores of vessels between seasons. More specifically we test whether the performance of individual vessels can be characterized as random or not; i.e., given good performance in one period, is it possible to also expect good performance in the next (a so-called "highliner"), or is performance due to the stochastic environment (fishing luck). [ABSTRACT FROM AUTHOR]