A Two-Constraint Almost Ideal Demand Model of Recreation and Donations
构建了一个同时受金钱和时间约束的不完全需求系统，用于分析娱乐和捐赠选择，并以加州观鲸者的旅行和捐赠数据为例，计算了环境质量改善的福利变化。
An incomplete demand system is developed for recreation and donation choices, subject to both money and time constraints. The model results in a three-good system, with an endogenous marginal value of time for estimation. The model is implemented by adapting Deaton and Muellbauer's locally flexible almost ideal demand system to a two-constraint recreation model of trips and donations of California whale watchers. Exact welfare measures are calculated for changes in costs, as well as for whale population changes. Results indicate a use and a nonuse component of overall willingness to pay for increases in environmental quality. © 2003 President and Fellows of Harvard College and the Massachusetts Institute of Technology.