Time Bias in Recreation Benefit Estimates

Abstract

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 ooe travel.

The recreational value of Lake McKenzie, Fraser Island: An application of the travel cost method

“…Since the very earliest applications of the travel cost method (see for example, Cesario and Knetsch, 1970;Cesario, 1976) the treatment of the cost of time, both travel time and time spent on-site, has been problematic. In its essence, the argument for including time costs within the travel cost framework is that, as a scarce commodity, the opportunity cost of time must be included and that failure to do so will increase the price elasticity of demand and therefore reduce the estimated benefits of visiting the recreation site (Freeman, 1993).…”

Valoración económica de la biodiversidad forestal en México, una revisión

“…El sesgo del tiempo ocurre cuando éste no se considera como un elemento de la conducta de los practicantes de la recreación (Cesario & Knetsch, 1970). La extensión del sesgo depende de la significancia de la variable omitida, en este caso tiempo de viaje, y la correlación entre la variable omitida y la variable retenida.…”

“…Time bias occurs when it is not considered as an element of the behavior of recreation practitioners (Cesario & Knetsch, 1970). The extent of bias depends on the significance of the variable omitted, in this case travel time, and the correlation between the variable omitted and the variable retained.…”

Accounting for stochastic shadow values of time in discrete-choice recreation demand models

“…To distinguish between over-and underemployed workers, those who worked fixed schedules and received a wage were asked, ''Would you be willing to work fewer hours in order to have more free time?'' 11 The breakdown of the sample by labor class is presented in Table 2. Almost three-quarters of the sample were full-or part-time workers, with the majority (80%) working full time.…”

“…At least since Cesario and Knetsch [11] discussed the biases to welfare estimates of recreation site values from ignoring time costs, researchers have attempted to account for this cost in recreation demand models. Most studies assume recreation time can be valued at the wage rate or at a fraction of the wage rate.…”