Around the globe, policymakers have long been concerned about the social and economic effects of an ageing population, and in particular the impact of a decline in labour market participation on pensions and other forms of income security. Technological improvements in medical diagnosis and treatment, better nutrition and other factors have increased healthy life, and this, coupled with a lowering birth rate, has led to an increase in consumption of health services and a decrease in the number of people entering the labour force. The proportion of people retired to those in work (the 'dependency ratio') is steadily increasing, and this affects how a society finances healthcare, long-term care, pensions and other social services. In 1987, The Geneva Association, in response to these trends created the 'Four Pillars' research agenda for rethinking healthcare and social security. In addition to the three pillars of contributory public pension, private occupational pension and individual savings, the Association identified the need to extend working life through a re-visioning of employment and retirement. Somewhat later, the Association launched another research project, Health and Ageing, to study interventions that maintain an active and healthy life after 65, as well as ways of organizing and financing long-term care. The complementary objectives of extending working life, and extending healthy life for work are based on the single social strategy of increasing the participation of older people in the workplace in order to spread the costs of ageing more equitably across the entire population. At the same time, increasing work participation and lowering unemployment are human rights objectives that underscore the importance of ensuring that everyone, regardless of age or functional capacity, participates fully in fundamental life activities. But both objectives also presume our ability to identify age-related functional decrements, to assess and measure them, and armed with this information, to devise interventions, strategies and policies that increase work participation. More is involved here than mere data collection. There is an important, and radical, conceptual reorientation that needs to be made. The relationship between an individual's functional capacities to work - his or her inherent work capacity - and the work environment and its demands is both interactive and negotiable. We normally think of people being 'fit for work' ; but we need also to think of work being fit for people. Although decrements in functional capacity can be ameliorated, or even