[3][4] In 1975, Treiman accepted an associate professor position in the Department of Sociology at the University of California, Los Angeles (UCLA) (1975-1977).
After being employed as a visiting scholar at the Universitat zu Koln in Germany (1977) and a senior lecturer at the International Social Science Council in Vienna (1977), Treiman returned to a professor position at UCLA (1977-2004).
[3][4] In 2009, Treiman was appointed Distinguished Professor Emeritus of the Department of Sociology at UCLA, a position he still holds.
In this book, Treiman introduced the concept that there is a high level of cross-national uniformity among evaluations of occupational prestige.
Treiman argued that the SIOPS is an accurate predictor of occupational prestige within each individual country and claimed a higher level of accuracy than alternative scales.
Treiman and colleagues argued that the ISEI performs similarly to alternative scales, including the SIOPS, in explaining occupational hierarchies cross-nationally.
Treiman and Ganzeboom created the International Stratification and Mobility File (ISMF), which serves as a comparative database.
Through the use of multiple intergenerational mobility tables from each country studied, Treiman and colleagues attempted to reduce the effects of measurement error.
With their findings, Treiman and colleagues challenged the concept of common social fluidity, which suggests homogeneity among mobility structures both geographically and temporally.
In 2008, Treiman conducted the Chinese Migration and Health Survey with colleagues William Mason, Shige Song, and Wang Wei.
Treiman and colleagues reported mixed conclusions on the relationship between migration and health, as they found that migrants had higher incomes on average than non-migrants and were more likely to access healthcare providers, but were less likely to be insured.
Overall, Treiman and colleagues concluded that the patterns and consequences of internal migration in China were similar to trends observed in other countries.
Treiman and colleagues designed and utilized The Urbanization and Child Development Study to argue the existence of this disparity.
Overall, Treiman and colleagues argue that internal migration patterns which disrupt family structures leave children developmentally vulnerable, therefore harming "the social development of the society.
He is the recipient of the 2012 Robert M. Hauser Distinguished Career Award and an Honored Colleague of the Population Association of America.