可以把“免费公交车”看做是一种 Publicly provided private good,funded by a tax (eg. Head tax)。
 假设有两种类型的个体:低收入者和高收入者。而“免费公交车”吸引低收入者使用,而同时又不吸引高收入者参与。实际上就是一种 In-kind transfer from rich to poor。
 具体的模型,可以参看 Timothy Besley & Stephen Coate, Public Provision of Private Goods and the Redistribution of Income",The American Economic Review, Vol. 81, No. 4. (Sep., 1991), pp. 979-984."
 [此贴子已经被作者于2006-9-19 23:18:21编辑过]