Structural stigma and the health and wellbeing of Australian LGB populations: Exploiting geographic variation in the results of the 2017 same-sex marriage plebiscite

Rationale: Lesbian, gay, or bisexual (LGB) people experience poorer life outcomes than heterosexual people, with ongoing debates about the aetiology of these differences. Minority stress theory draws attention to the importance of structural stigma, which concerns hostile social environments for sexual minorities that constrain their opportunity structures. Yet few studies have operationalised structural stigma and tested its influence, with most focusing on the US context; even fewer studies examine the underlying mechanisms. Objective: This study expands the available evidence to Australia, which constitutes an interesting case study due to the implementation in late 2017 of a national postal plebiscite on same-sex marriage legislation. It also adds to knowledge by theorising and testing the mediating role of perceived social support in explaining the association between structural stigma and the life outcomes of LGB people. Method: The analyses leverage geographical variation at the electorate level (n = 150) in the share of ‘No’ voters in the plebiscite as a measure of structural stigma. This aggregate-level information is merged to individual-level data from the Household, Income and Labour Dynamics in Australia Survey, a large, national probability sample (n∽15,000). Results: Multilevel regression models yield results which are consistent with minority stress theory and previous US scholarship: LGB people report comparatively worse life satisfaction, mental health and overall health in constituencies with higher shares of ‘No’ voters, controlling for a large set of individual- and aggregate-level confounds. Perceived social support mediates a large portion of the effects of structural stigma on LGB outcomes. Conclusion: These findings have significant implications for policy and practice, highlighting the need for interventions aimed at reducing community levels of structural stigma and increasing social support to LGB populations