Why Cooperate? Public Goods, Economic Power, and the Montreal Protocol
用相关概率模型分析各国是否批准蒙特利尔议定书的决策，发现多数国家并非受他国行为影响，拒绝了搭便车动机。
This paper develops a correlated probit model to describe dichotomous choices that may contain a public-goods component or some other forms of interdependency. The key contribution of the paper is to formulate tests for interdependent behavior among agents. In particular, we examine the decisions by nations whether or not to ratify the Montreal Protocol on Substances that Deplete the Ozone Layer. Specifically, we reject free riding as a motive for not ratifying the Protocol, and we find little evidence that individual nations were influenced by the behavior of their largest trading partners. Hence, the data suggest that, with respect to the Montreal Protocol, most nations acted without regard for the actions of other nations. © 2003 President and Fellows of Harvard College and the Massachusetts Institute of Technology.