Time Bias in Recreation Benefit Estimates

Indirect methods are generally necessary to measure outdoor recreation benefits. A widely proposed technique involves estimating demand schedules using travel cost data as a proxy for prices. A major problem involved with this method as it has been applied is a serious conservative bias in the estimates, owing to the improper accounting of the constraint imposed by time costs on recreational visits. The bias is examined and corrections are suggested that could improve the estimates. The degree of ultimate improvement seems to depend on better data and on an understanding of the trade-off function between time and cost outlays for this form of travel.