In the absence of a survey designed and dedicated to the collection of information to assess the status of social mobility, a wide variety of data sources designed for other purposes have been pressed into service in order to illuminate the state of social mobility and its trends. Developing New National Data on Social Mobility discusses the key decision points associated with launching a new national level survey of social mobility. This report considers various aspects of a major new national survey, including identifying relevant new theoretical perspectives and technical issues that have implications for modeling, measurement, and data collection.