Immigrant Earnings Assimilation
Also known as: Earnings Assimilation Profile, Years-Since-Migration Earnings Model, Chiswick-Borjas Cohort Method, Immigrant Wage Catch-Up Analysis
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.
Key highlights
- Provides a clear, quantifiable measure of immigrant economic integration through the years-since-migration earnings profile and overtaking point.
- The cohort correction exposes and removes a fundamental bias, distinguishing true wage growth from changes in arrival-cohort quality.
- Synthetic cohorts exploit widely available repeated cross-sections, enabling longitudinal inference without true panel data.
- Anchors policy evaluation by linking measured assimilation to shifts in selection, source countries, and admission criteria over time.
Intuition
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How it works
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When to use it
Use immigrant earnings assimilation analysis when you want to measure how immigrants' wages converge toward, or diverge from, those of natives over time in the host labor market. A single cross-section suffices for a descriptive earnings profile and overtaking estimate, but you should reach for the cohort method whenever arrival quality may have shifted across entry years — which is almost always — and you have repeated cross-sections or panel data to build synthetic cohorts. The framework is the natural choice for evaluating immigration policy, source-country composition, and the economic integration of the foreign-born. It is less appropriate when you lack any information on year of arrival or years since migration, when earnings are not the outcome of interest, or when selective return migration is so strong that the surviving cohort is unrepresentative of who originally arrived.
Strengths & limitations
- Provides a clear, quantifiable measure of immigrant economic integration through the years-since-migration earnings profile and overtaking point.
- The cohort correction exposes and removes a fundamental bias, distinguishing true wage growth from changes in arrival-cohort quality.
- Synthetic cohorts exploit widely available repeated cross-sections, enabling longitudinal inference without true panel data.
- Anchors policy evaluation by linking measured assimilation to shifts in selection, source countries, and admission criteria over time.
- Age, period, and cohort effects are not separately identified without an additional, often untestable, normalizing assumption.
- Selective return migration can bias cohort estimates, since those who stay differ systematically from those who leave.
- Synthetic cohorts assume the surveyed cohort is stable in composition across surveys, which migration and mortality violate.
- Cross-sectional estimates remain common despite the cohort critique and can substantially overstate the speed of assimilation.
Common pitfalls
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Applications
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Frequently asked
What was Chiswick's original finding and why was it influential?
Using a single 1970 cross-section, Chiswick estimated a human-capital earnings equation for foreign-born men and found that their earnings, initially below those of comparable natives, rose steeply with years since migration and overtook native earnings within roughly fifteen years. He interpreted this as rapid acquisition of host-country-specific skills plus favorable self-selection of immigrants. The result was influential because it suggested immigrants integrated economically and even outperformed natives, supporting an optimistic view of immigration that dominated until Borjas challenged the cross-sectional logic.
What exactly is the cohort-quality bias Borjas identified?
In a single cross-section, the years-since-migration slope compares long-settled immigrants with recent arrivals — but these are different cohorts that entered in different eras, not the same people aging in place. If the skill or quality of successive arrival cohorts declined over time, the long-settled will earn more partly because they were a better cohort, not only because they assimilated. The cross-section then attributes this cohort difference to assimilation, overstating wage growth. Borjas showed the bias is real and large enough to overturn the rapid-overtaking conclusion.
How do synthetic cohorts fix the problem?
A synthetic cohort follows the same arrival cohort across two or more repeated cross-sections, such as successive censuses. Because you observe the cohort at two dates, the change in its average earnings measures within-cohort wage growth directly, isolating assimilation from the composition differences that contaminate a single snapshot. Pooling the surveys with arrival-cohort and period effects lets you estimate assimilation net of cohort quality, though you must still impose an assumption to separate age, period, and cohort, and watch for selective return migration that erodes the cohort over time.
Sources
- 1.Chiswick, B. R. (1978). The Effect of Americanization on the Earnings of Foreign-Born Men. Journal of Political Economy, 86(5), 897-921.
- 2.Borjas, G. J. (1985). Assimilation, Changes in Cohort Quality, and the Earnings of Immigrants. Journal of Labor Economics, 3(4), 463-489.
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Cite this page
ScholarGate. (2026, June 23). Immigrant Earnings Assimilation. ScholarGate. https://scholargate.app/migration-studies/immigrant-earnings-assimilation