This paper considers testing the unit root hypothesis against a smooth transition autoregressive model as the alternative. The model specification makes it possible to discriminate between nonstationary random walk and stationary nonlinear processes. Some new limit results are presented,...

The value of preventing a fatality or (saving) a statistical life is an important question in health economics as well as environmental economics. This paper reviews and adds new insights to several of the issues discussed in the literature. For example, how do we define the value of a...