The potential effects of legal and unauthorized international migration on the census and other data sources in the United States: Methodological and policy issues in 2010 and beyond

Abstract

This article considers the accurate measurement of international migration to and from the United States, both legal and unauthorized, and how these measurement characteristics might affect the accuracy and utility of the 2010 census and other data sources. It provides a brief overview of the recent magnitude and impacts of US immigration. It delineates the role of immigration in determining an accurate census and discusses specific parameters that must be accurately measured in order to adequately assess immigration, both legal and unauthorized. It makes specific recommendations for addressing the effects of such factors. Migration is widely recognized as the most difficult demographic component to measure in determining demographic change in the United States [39,40]. This is, in part, a result of the fact that the United States does not have a registration system for internal migration (as exists in some countries) and because of the magnitude and characteristics of international migration in the United States [57]. Although both internal and international migration are difficult to measure, international migration provides especially difficult challenges because the system for the collection of data on immigration is not adequate for demographic purposes and because an important form of immigration, unauthorized immigration, has become increasingly contentious, resulting in multiple interpretations of available data and considerable levels of misleading and erroneous information. Addressing such challenges is of increasing importance because of the historically high levels of immigration in the United States, including large numbers of unauthorized immigrants, and because the measurement of immigration has been a major source of error in estimates of recent populations. Thus, the Census Bureau underestimated the US population in 2000 by almost 7 million [44], in large part, because of its inability to measure the effects of unauthorized immigration. The focus in this article is on how the accurate measurement of international migration (including both that to and from [emigration from] the United States and legal and unauthorized) may affect the accuracy and utility of the 2010 Census and other data sources and on what steps might be taken to minimize such effects. The article begins with a brief overview of the recent magnitude and impacts of legal and unauthorized immigration in the United States and of literature on specific