"Equally Available to Anyone": The Invention of Public Use Data Microdata at the U.S. Census Bureau, Version 2

This research note explores the creation of the first census microdata sample at the U.S. Census Bureau in the early 1960s. This sample and its successors have had a profound impact on demographic research over the past six decades. The invention of microdata was a product of close communication and collaboration between the research community and Census Bureau staff. In particular, interactions at the Population Association of America played a central role in the development of microdata. Drawing on historical evidence from the National Archives—including Census Bureau internal memoranda, technical advisory committee minutes and correspondence, academic association minutes, as well as a variety of secondary and primary source materials gathered from public and private collections—our research uncovers the history of the people and motivations behind the development of U.S. Census microdata.