From: Immigration and wages: new evidence from the African American Great Migration
Sample |  | 1940–1960 | 1940–1970 |
---|---|---|---|
Whites | \(-\sigma _{i}^{-1}\) | −0.05 | −0.05 |
 |  | (0.06) | (0.04) |
 | N | 117 | 156 |
Blacks | \(-\sigma _{i}^{-1}\) | 0.05 | 0.02 |
 |  | (0.08) | (0.05) |
 | N | 117 | 156 |
Pooled | \(-\sigma _{i}^{-1}\) | −0.04 | −0.04 |
 |  | (0.06) | (0.04) |
 | N | 234 | 311 |