Data and Methods
DATA AND SAMPLE SELECTION The data used for this study are taken from the U.S. Census 1990 Public Use Microdata (A) Sample (PUMS-A). The PUMS-A is a sample of census records for 5 percent of the housing units in the United States and the people in them. The PUMS contains records of both people and housing units, although only person records will be used in this analysis. This data set was selected because it contains relatively detailed immigration and labor force data and is sufficiently large to study small sub-populations in each of the enclave and non-enclave areas of interest.