The impact of measurement assumptions upon individual travel cost estimates of consumer surplus: a GIS analysis

The individual travel cost method is one of the most commonly applied approaches to estimating the recreational value (or 'consumer surplus') of open-access sites where the visitor does not have to pay an entrance charge for using the area. This paper presents a simple application of the method conducted using geographical information system (GIS) software. This approach permits analysis of the impact of various, commonly used, assumptions concerning the definition of visitor outset origins and routing to recreation sites. Results suggest that varying these assumptions can lead to substantial impacts upon estimates of consumer surplus to the extent that previously published studies may be subject to substantial error.