A Site-Portfolio Model for Multiple-Destination Recreation Trips: Valuing Trips to National Parks in the Southwestern United States

We propose a new method for analyzing multiple-destination recreation trips and apply it to visitation at national parks in the southwestern United States. We use conventional random utility theory and treat groups of parks (portfolios) as choice alternatives. We consider one choice occasion per respondent and condition that choice on the person visiting at least one park in the choice set, so the participation decision (go/no-go) is not modeled. Trip cost includes time, travel, lodging, and food cost for visiting all sites in the portfolio. Variation in trip cost is generated by variation in the location where individuals enter and exit the southwestern region and by variation in the specific set of parks in each portfolio. We use specialized sampling weights to correct for on-site sampling. Finally, we provide estimates of per trip losses for closing one or more of the parks.