Identifying changes in the compositions of families over long periods of time is one of the most difficult challenges facing social and population scientists. Even the most extensive longitudinal sources of data, such as the Panel Survey of Income Dynamics or the National Longitudinal Surveys of Youth (1979 and 1997), cannot precisely measure changes in family composition over time because the full array of intra-family relationships are left unmeasured in these and other data collections. Consequently, though population scientists and sociologists know much about the transformation of families over the last 30 years, there is still a large gap in the measurement of family change due to data constraints and a limited range of methodological approaches. This paper argues that by innovatively combining existing sources of household survey data at distant points in time and by adopting statistical methods, which are noticeably under-utilized in the social sciences, this gap in our understanding of family change and variation can be narrowed significantly. The paper could have drawn on data from the USA, Canada, and the UK, but the best demonstration of the combining of datasets, the statistical methodology, and the substantive implications for family change research come from utilizing two superior Australian data sources separated by 30 years. In this paper, the 9th wave (2010) of the Household, Income, and Labour Dynamics in Australia (HILDA) Survey and the 1980 Australian Institute of Family Studies Family Formation Survey (AIFS) datasets are utilized. With federal funding for new data collections on families severely curtailed, this paper suggests a cost-effective and efficient empirical strategy for explaining family change.