Looking upstream for influences on socioeconomic inequalities in health.

The authors of a recent article on health and urban planning observed that ‘[r]ich and poor people live in very different epidemiological worlds, even within the same city’. The authors did not elaborate upon or theorize this point, but it is more than a statement of the obvious and underscores the importance of explaining health inequalities with reference to complex sets of exposures and vulnerabilities that occur simultaneously or sequentially, vary across socioeconomic gradients, and have effects that often accumulate over the life course. In this issue, the study of Detroit by Kwarteng et al. adds an important contribution to the literature on how the physical condition of neighbourhoods influences residents’ physical activity. Similar to many findings, this should direct our attention to macro-scale social and economic influences such as deindustrialization, rising economic inequality, racial segregation and the sorting effects of housing markets. As geographer Tom Slater has argued: ‘If where any given individual lives affects their life chances as deeply as neighbourhood effects proponents believe, it seems crucial to understand why that individual is living there in the first place’ (emphases in original). A recent editorial and forthcoming research article in the Journal describe differences in the epidemiological worlds typical of England’s distinct regions, whilst simultaneously suggesting the need for further investigation both of intra-regional differences and of social and economic policies that magnify economic inequalities or exacerbate regional divides. Arguably, these exemplify the ‘toxic combination of poor social policies and programmes, unfair economic arrangements, and bad politics’ identified by the WHO Commission on Social Determinants of Health as a root cause of health inequalities. Evidence is accumulating that trade policy can contribute to the persistence and widening of those inequalities, especially if its consequences for health are not rigorously assessed. Also in this issue, Greenberg and Shiau argue that the Trans Pacific Partnership Agreement is being negotiated without enough attention to those consequences, partly because of a lack of transparency in the negotiation process and partly because of inadequate awareness on the part of public health researchers and practitioners—at least in the USA—of the connections between trade policy and health. The implication is that understanding influences on future epidemiological worlds, and the differences among them, requires looking upstream not only at a broad range of domestic policies but also at the commitments governments make in the international arena on behalf of their citizens. Closer to home, this issue of the Journal also features, under its Behavioural Factors heading, a focus on alcohol, with a guest editorial from Stephanie Scott and Eileen Kaner. As they correctly point out, this is a huge problem often overlooked in comparison to other major public health issues. We expect to return to it regularly.