Comparison of proxies for fish stock. A Monte Carlo analysis

In fisheries, it is quite common to include a measure of fish stock as an argument of fishing production functions. Given that this information is not available in many cases, researchers use stock proxies. We show that catch-per-unit-effort, a common proxy based on the average catch of boats in a given period, introduces strong parametric restrictions when included as an explanatory variable in a linear production function. However, a proxy based on time dummy variables yields unbiased estimates of the effect of stock on catch. An empirical section that uses Monte Carlo simulation corroborates the theoretical results.