Measuring Interstate Migration Flows: An Origin—Destination Network Based on Internal Revenue Service Records

Abstract

This paper examines gross interstate migration flows for five periods for the years between 1969 and 1978. The analysis is based upon a newly available data source—Federal income tax returns. Approximately 90% of the US population is covered by this data series. The matching of Internal Revenue Service (IRS) returns between filing dates enables the determination both of the origin and of the destination of migrants, with few of the risks of geographic miscoding present. These data illustrate that despite divergent economic fluctuations over the past nine years, the patterns of interstate migration have remained virtually unchanged. With few exceptions, the number of migrants either leaving or entering a particular state comprise identical proportions over time. Unlike migration data obtained from the Current Population Survey which enables the study of regional mobility only, the IRS data document current state-to-state flows that can be constructed on an annual basis. Comparisons are also made with the Current Work History Sample. In addition, these data offer considerable evidence that current residence has a significant impact on the selection of a destination. The resistance of migration patterns to large economic and social shifts during the period examined also implies that the explanation of individual migration determinants and the forecasting of aggregate migration flows should be treated as separate research questions. The potential of the data for the addition of further demographic detail and for use in forecasting also is considered.