Can I study multiple countries? One country?
IPUMS-International is designed to facilitate cross-national and cross-temporal research, but there is no restriction against single-country studies. Data extracts can contain records from every sample in the entire data series, or records from only a single sample. Researchers interested in studying only the United States, however, would be best served by going to IPUMS-USA, which is optimized for U.S. research and has greater temporal depth.