The study used data derived from the public use microdata sample (PUM) files for 1990, 1% and 5% samples. Ethnic groups were classified into 10 broad categories: Central America and Mexico, South America, Other Hispanic, Caribbean, Sub-Sahara Africa, N. Africa and Mid. East, Asia, North America, Northern and Western Europe, and Eastern and Southern Europe. Occupation categories included were as follows: Executive, Administrator, and Manager; Management-related; Professional; Technical; Sales; Administrative Support; Protective Services; Food Service; Health Services; Cleaning and Building; Personal Services; Farming, Forestry, Fishery; Mechanics and Repairers; Construction Trade; Extractive; Precision Production; Machine Operators, Assemblers; Transportation and Material Moving; and Laborers and Private Household.
The analysis found that most of the Hispanic groups were concentrated in service (food, health, cleaning and building) and blue-collar (machine operators and assemblers, laborers) jobs. More specific findings indicate that persons of Guatemalan, Honduran, Argentinean, Chilean, and Panamanian ethnicity were concentrated in construction trades. Administrative support jobs were over-representatively occupied by Puerto Ricans, Cubans, and other Hispanics. Persons of Caribbean ancestry were concentrated in health services, administrative support, and laborer occupational sectors. Middle Eastern and Asian groups were concentrated in professional and retail occupations. Vietnamese were over-representatively working in semiskilled blue-collar occupations. American Indians, Hawaiians, and Canadians were clustered in construction trades, and transportation and material moving. European ethnic groups were concentrated in white-collar occupations.
Wilson used Multi-city Study of Urban Inequity (MCSUI) surveys to explore the extent to which persons work in jobs at jobs that are ethnically homogeneous, and any associations between ethnic niches and ethnically homogenous workforces. The surveys were conducted in 1992-1994 in Atlanta, Boston, Detroit, and Los Angeles.
Several implications that Wilson derived from this study are that ethnic niching is a “social formation driven by the needs of ethnic groups to acquire material resources beneficial to the well-being of members” and the necessity of maintaining those members’ access to resources; that the structure of labor markets facilitate the matching of individual workers’ skills and experiences with the goods and services labor market positions; and that employers, who seek to maintain productivity goals, may recruit a certain group in order to minimize doubt of the labor supply quality.