This paper draws on two linked studies of social policy and wellbeing in later life. The studies make comparisons between distinct groups of older people at the national and sub-national levels, as well as over time. The paper reflects on some of the main challenges for operationalising this complex design, as well as for interpreting findings and identifies lessons for other studies. The first study, conducted in 2002, included a questionnaire survey of around 2000 households containing at least one older person in South Africa and Brazil, supplemented by a set of in-depth qualitative interviews. Intriguingly, these countries had remarkably similar pension programmes, providing the majority of older people a reliable payment of roughly US$3 a day. This offered the prospect of exploring the effects of similar interventions in distinct developmental and cultural settings. In both countries, we found that these pensions had a substantial impact on the prevalence and depth of poverty in the study households, and were usually shared between older people and other family members. The second survey took place in 2008/9 and involved revisiting the households included in the 2002 survey, along with a separate set of in-depth interviews. This provided an opportunity for dynamic analysis of economic and wellbeing effects, against a backdrop of increased divergence in the wider national settings. Among other things, this revealed high and increasing levels of life satisfaction across all the study groups, although the extent to which this was directly related to generous pension provision cannot be ascertained.