Discoveries and challenges from Census 2000

Betsy Guzmán, U.S. Census Bureau
Kevin Deardorff, U.S. Census Bureau
Melissa Therrien, U.S. Census Bureau

Census 2000 shattered our assumptions about international migration in the United States during the 1990s and has challenged us to find new methods and/or data sources. Before the decennial census, the U.S. Census Bureau had used established methods to calculate the international migration component for use in our annual population estimates. The results of Census 2000 spurred a variety of research to trace the reason for the discrepancy between our estimated population and our enumerated population. In the end, we found that the two largest sources of error were coverage in the census and accounting for international migration during the period between censuses. These findings have provided opportunities for us to think creatively about new data sources and new methodologies to estimate international migration. This paper outlines the previous methodology, the findings from the research after Census 2000, and the current research agenda.