Immigrant Earnings Assimilation

Immigrant earnings assimilation analysis asks how the wages of the foreign-born evolve relative to comparable natives as immigrants spend more years in the host country. Barry Chiswick's 1978 study established the canonical approach: regress log earnings on years since migration and human-capital controls, and interpret the upward years-since-migration profile as evidence that immigrants acquire host-country-specific skills, language, and labor-market knowledge, eventually 'overtaking' similar natives. George Borjas's 1985 critique exposed a deep flaw in reading this from a single cross-section: the positive slope could reflect not within-person growth but a decline in the unobserved quality of successive arrival cohorts, so that earlier, higher-earning immigrants merely make recent arrivals look like they are catching up. Borjas's remedy was to track fixed arrival cohorts across repeated cross-sections — synthetic cohorts — disentangling genuine assimilation from compositional change. The method thus has two layers: a within-survey earnings profile and a cross-survey correction that separates true wage growth from shifts in who is arriving. It remains the foundational empirical framework in the economics of immigration.