RESUMO
The ethnic density thesis suggests a protective health benefit for ethnic minorities living in places with higher concentration of co-ethnic residents. This paper aims to make a step change in the examination of this thesis by proposing ethnic diversity rather than co-ethnic density will be more protective for mental health. The paper proposes ethnic diversity could be a community asset that benefits the health of all people in a neighbourhood regardless of their own ethnic group. Individual data is taken from the UK Household Longitudinal Study, 2009-2019 linked to aggregate data from the 2001 and 2011 Censuses to test the association between co-ethnic density, ethnic diversity and mental health using the General Health Questionnaire 12-item scale. The paper takes a novel approach by measuring pre-existing (in 2001) and change in (2001-2011) co-ethnic density and ethnic diversity. Moderating effects of individual ethnic group, neighbourhood deprivation and perceived social cohesion are tested. Results show lower pre-existing co-ethnic density is related to lower mental health amongst the White British ethnic group but not in most ethnic minority groups. Greater pre-existing ethnic diversity in more deprived neighbourhoods is associated with better mental health regardless of individual ethnic group. A point of contention in the findings is no association between change in ethnic diversity and mental health.