Modeling Multiple-Objective Recreation Trips with Choices over Trip Duration and Alternative Sites CHIA-YU YEH 1 , TIMOTHY C. HAAB 2 and BRENT L. SOHNGEN 2, * 1 Economics Department, National Chi Nan University, Taiwan; 2 Agricultural, Environmental, and Development Economics, Ohio State University, Columbus, OH, USA; *Author for correspondence (E-mail: Sohngen.1@osu.edu) Accepted 2 December 2005 Abstract. Traditionally, recreation demand studies have focused on single-day, single-activity trips, despite anecdotal and empirical evidence that many recreational trips involve overnight stays and multiple purposes. This paper develops a random utility model that explores how visitors choose alternative sites and trip durations for multiple-objective trips. We focus on a recreational activity, beach visits, that appear to have significant proportions of the popula- tion taking single and multiple-day trips, and many of the multiple day trips involve multiple objectives. Multiple-duration and multiple-objective issues are incorporated in pricing trip costs. The results of the research suggest that the accepted method for incorporating travel costs into random utility models can lead to biased estimates of the structural utility parameters and, consequently, biased measures of welfare in a multiple-objective trip setting for single- and multiple-day users. Key words: beaches, multiple durations, multiple objectives, random utility model, recreation demand 1. Introduction Recreational demand studies tend to focus on single-day, single-activity trips, despite anecdotal and empirical evidence that many recreational trips involve overnight stays and multiple activities. When multiple-day trips clearly have a single objective (i.e., to visit a single recreational site, or to participate in a particular recreational activity), trip duration can be treated as a separate choice, as suggested by Shaw and Ozog (1999), and it is feasible to attribute the entire cost of a trip to the main recreational activity. In many recreational situations, however, visitors have multiple objectives for a given trip. For example, visitors may visit different types of recreation sites, such as beaches or parks without beaches, or they may engage in a range of activities like visiting family, going to amusement parks, etc. In this circumstance, it is Environmental & Resource Economics (2006) 34: 189–209 Ó Springer 2006 DOI 10.1007/s10640-005-6205-1