A new conceptualization of ethnicity for social epidemiologic and health equity research.

Although social stratification persists in the US, differentially influencing the well-being of ethnically defined groups, ethnicity concepts and their implications for health disparities remain under-examined. Ethnicity is a complex social construct that influences personal identity and group social relations. Ethnic identity, ethnic classification systems, the groupings that compose each system and the implications of assignment to one or another ethnic category are place-, time- and context-specific. In the US, racial stratification uniquely shapes expressions of and understandings about ethnicity. Ethnicity is typically invoked via the term, 'race/ethnicity'; however, it is unclear whether this heralds a shift away from racialization or merely extends flawed racial taxonomies to populations whose cultural and phenotypic diversity challenge traditional racial classification. We propose that ethnicity be conceptualized as a two-dimensional, context-specific, social construct with an attributional dimension that describes group characteristics (e.g., culture, nativity) and a relational dimension that indexes a group's location within a social hierarchy (e.g., minority vs. majority status). This new conceptualization extends prior definitions in ways that facilitate research on ethnicization, social stratification and health inequities. While federal ethnic and racial categories are useful for administrative purposes such as monitoring the inclusion of minorities in research, and traditional ethnicity concepts (e.g., culture) are useful for developing culturally appropriate interventions, our relational dimension of ethnicity is useful for studying the relationships between societal factors and health inequities. We offer this new conceptualization of ethnicity and outline next steps for employing socially meaningful measures of ethnicity in empirical research. As ethnicity is both increasingly complex and increasingly central to social life, improving its conceptualization and measurement is crucial for advancing research on ethnic health inequities.