Greater neighborhood co-ethnic density (living in proximity with people sharing an ethnicity) and being foreign-born each can protect against risky drinking, but little is known about whether these two factors interact. Using a representative sample of Latinos and Asians from California, authors investigate main and interactive effects of neighborhood co-ethnic density and nativity status in relation to heavy episodic drinking (HED).

This study uses pooled 2011–2015 pooled California Health Interview Survey (CHIS) neighborhood data to investigate associations of co-ethnic density and nativity status with HED. Co-ethnic density was based on matching each respondent's ethnicity to the proportion of residents of the corresponding group in their Census tract. Authors first examined main effects of neighborhood co-ethnic density and respondent nativity status on HED. They assessed the interaction of co-ethnic density and nativity status. Finally, authors estimated nativity-stratified models investigate variation in effects of co-ethnic density.

Findings: Co-ethnic density was not associated with HED for the full sample, but U.S.-born nativity status was associated with increased odds of past-year HED. The interaction model showed co-ethnic density and nativity had synergistic effects, whereby greater levels of neighborhood co-ethnic density buffered risk associated with being U.S.-born. Further, greater neighborhood co-ethnic density was associated with reduced odds of HED for US-born respondents, but it was not associated with HED for foreign-born respondents.

Protective effects of high neighborhood co-ethnic density on HED are stronger for U.S.-born than for foreign-born Latinos and Asians in California.