This paper focuses on possible economic consequences of low fertility in Europe. It summarizes a selection of papers that were presented at a conference at the University of St. Gallen in April 2008. This introduction also reviews the history of falling fertility in Europe and the literature that explores its causes, its potential implications, and possible policy responses. It summarizes the evolution of thinking about the relationship between population growth and economic development, with attention to recent work on the mechanisms through which fertility decline can spur economic growth if the necessary supporting conditions are met. The paper also identifies some of the challenges of population aging that are associated with low fertility and suggests that there may be less reason for alarm than has been suggested by some observers.