Multiple perceptible signals from a single olfactory glomerulus.

Rapid rates of population ageing across countries represent both challenges and opportunities for governments concerned about the health and healthy ageing of increasingly older populations (). In addition to expenditure on health care and social care, welfare entitlements are another avenue through which governments can contribute to the health of their older citizens. Programmes or systems designed to alleviate poverty in retirement, such as non-contributory pension schemes, can improve the quality of life of low-income pensioners by increasing their household incomes and, through this mechanism, access to necessities, ability to cope better in emergencies and reducing financial worries (; ). This is important as less anxiety over finances, and better overall health have been correlated with lower levels of depression and psychosocial distress and higher mental wellbeing (; ). In accordance with this, several studies across high and middle income countries have found positive effects of welfare reforms which increase pension income on the mental health of pensioners (for a systematic review see ). These effects, however, are not uniformly recorded across social groups. In a study of an expansion in pension benefits for a US cohort of low-education pensioners, instrumental-variables estimates showed a positive effect of an additional US$1,000 of Social Security income on depression scores and probability of experiencing depression in women, but no effects of the increase in incomes in men. In a similar context to our study, applied a difference-in-difference estimator with instrumental variables and found positive effects for men of the introduction of a non-contributory means-tested pension for low-income individuals facing retirement in Chile, but no effects of the increase in expected pension wealth on women’s mental health outcomes. Differences have also been observed by education level of the household reference person, and by baseline level of cognitive health (). These and other potential heterogeneities in the effects of welfare reforms on mental health have implications for mitigating or intensifying health inequalities in old age. In England, men and women over the age of 65 residing in the most deprived neighbourhoods can expect to live on average five years less than their peers in the least deprived areas of the country (). Simultaneously, while pensioners’ poverty is less localised than poverty in other age groups, it tends to concentrate spatially in more deprived areas (). This geographical heterogeneity among the elderly arises from individual and spatial inequalities in the distribution of the social determinants of health (e.g., income, employment, housing, access to health care, etc.) (; ; ) over the life course. To the extent that welfare reforms - such as changes to pension income - affect these underlying factors, they can be expected to impact area-level health inequalities in old age. The relationship between public transfers and inequalities in health in the elderly remains under-explored within the literature, particularly in terms of inequalities in mental and psychological wellbeing by area deprivation. Differences in the effect on individuals’ wellbeing of a change in income by area deprivation may be expected from a materialist perspective. More specifically, an increase in pensions may have a greater effect on the wellbeing for pensioners with the lowest incomes because this group would have had more difficulties in accessing crucial everyday necessities that now become more affordable (; ). Alternatively, differences by area deprivation may also be expected from a psychosocial perspective. That is, seeing one’s income increase compared to others in the neighbourhood () – as well as feeling more financially secure. This effect potentially will be stronger when it is a low-income neighbourhood ().