The Big Census Data Revolution: IPUMS-International. Trans-Border Access to Decades of Census Samples for Three-Fourths of the World and more.

Over the past decade a revolution has occurred in the dissemination and analysis of census microdata. This paper discusses the IPUMS-International initiative to liberate census data for researchers world-wide without cost. As of June 2013, academic researchers and policy makers may access, 234 anonymized samples representing 74 countries and totaling over one-half billion person records. The database expands with the addition of 20-30 samples each year. Data are downloadable as extracts from the project website: www.ipums.org/international. To facilitate good use, both metadata and microdata are integrated. The analysis of 450 citations in the project bibliography reveals patterns in publications by country and topic.