The joint effect of ethnicity and gender on occupational segregation : an approach based on the Mutual Information Index

This article studies the effects of gender and ethnicity on occupational segregation. The traditional approach to this topic measures the two sources of segregation separately. In contrast, we measure the joint effect of gender and ethnicity by applying a multigroup segregation index–the Mutual Information or M index–to the product of the two genders and seven ethnic groups distinguished in our census data for England and Wales in 2001. We exploit M's strong group decomposability property to consistently pose the following two questions: (i) How much does each source contribute to occupational segregation, controlling for the effect of the other? (ii) Is the combined impact of gender and ethnicity greater than, equal to, or smaller than the sum of their individual effects? The main empirical findings are the following two. First, we confirm previous results showing the greater importance of gender over ethnicity as a source of occupational segregation. However, we find that ethnicity contributes 13.5 percent of overall segregation in geographical areas where minorities concentrate. Second, contrary to intersectionality theories, we find that there is a small, “dwindling” interaction effect between the two sources of segregation: ethnicity slightly weakens the segregative power of gender, and vice versa.