The IPUMS big data revolution: liberating, integrating and disseminating the globe’s census microdata free of cost

Fifty years ago, census microdata were available for only a handful of countries and trans-border access was difficult for all but a few. Now, from www.ipums.org, many decades of census microdata for much of the globe are readily accessible anywhere, free of cost to researchers and students - regardless of country of birth, residence, or citizenship. As of late - 2013, 238 samples representing 74 countries, totaling more than one half billion person records and encompassing more than four fifths of the world's population are available to more than 7,000 registered researchers worldwide. Pioneers of demography developed national and even regional databases for analyzing census microdata (Ruggles 2013), but it is IPUMS that developed the first integrated system for global access. The IPUMS big data revolution, foretold a decade ago (McCaa and Ruggles 2002), has arrived, but is not yet complete. 50 years hence it is likely that almost all census microdata around the globe will be integrated and accessible via multiple systems of access using application programming interfaces (API).The revolution has already sparked much new research. According to a former president of the Population Association of America, students of the Big Census Data Revolution, specifically those with analytical experience using integrated census microdata, enjoy advantages for internships and employment at the World Bank and similar agencies (Meier, Lam, and McCaa 2011). Likewise, Dot-Coms beckon as a new jobs frontier opens for savvy Big Data users (Lohr, 2012:B2).