In this article, the authors clarify and provide additional tests of the key elements of their age-period-cohort analysis of non-marital birth rates in this March 2009 issue of "Social Forces." Where Steve Martin, in his commentary, has suggested specific alternative specifications or interpretations of their findings, the authors have…

Global economic transformations have never been as dramatic as in the twentieth century. Most countries have experienced radical changes in the standards of income per capita, technology, fertility, mortality, income inequality and the extent of democracy in the course of the past century. It is the goal of many disciplines--economics, history,…