USING ACTUAL AND CONTINGENT BEHAVIOR DATA WITH DIFFERING LEVELS OF TIME AGGREGATION TO MODEL RECREATION DEMAND

A model of recreation demand is developed to determine the role of wat er levels in determining participation at and frequency of trips taken to various federal reservoirs and rivers in the Columbia River Basin. Contingent behavior data are required to break the near-perfect multi collinearities among water levels at some waters. We combine demand da ta for each survey respondent at different levels of time aggregation (summer months, rest of year, and annual), and our empirical models ac commodate the natural heteroskedasticity that results. Our empirical r esults show it to be quite important to control carefully for survey n onresponse bias.