# County-to-county migration is associated with county-level racial bias in the United States

## TL;DR

Migration between U.S. counties is linked to changes in racial bias in the new locations, suggesting that people bring cultural attitudes with them.

## Contribution

This study demonstrates that migration influences regional racial attitudes over time, even after accounting for pre-existing biases.

## Key findings

- Migration from one county to another positively predicts increased racial bias in the destination county.
- The effect of migration on racial bias is consistent across three time periods (2006–2010, 2011–2015, and 2016–2020).
- The findings remain robust after controlling for pre-migration racial bias levels in counties.

## Abstract

Millions of people move within the U.S. each year. We propose that people function as proxies for their locations, bringing the culture of their previous residence to their new homes. As a result, migration might systematically influence regional biases across geographic units over time. Using county-to-county migration data from the U.S. census and county-level racial attitude estimates from Project Implicit, the present research examined the impact of people relocating from one U.S. county to another on racial attitudes in their new county. Consistent with our prediction, the bias brought by the migrants positively predicts county-level racial bias after migration, even after controlling for county-level racial bias before migration. This finding remains robust across various sample inclusion criteria and spans three time periods (2006–2010, 2011–2015, and 2016–2020). These results highlight the significant role of migration in spreading and shaping regional racial attitudes, emphasizing the importance of considering macro-societal processes such as migration when studying changes in regional racial attitudes.