The parametric model introduced by Lee and Carter in 1992 for projecting mortality rates in the US has been a seminal development and has been widely used since then. Different versions of the model, incorporating constraints on the data, and different adjustment methods have led to improvement....

We contrast two potential explanations of the substantial differences in entrepreneurial activity observed across geographical areas - entry costs and external effects. We extend the Lucas model of entrepreneurship to allow for heterogeneous entry costs and for externalities that shift the...