Why the more we tackle ageing, the more it matters

The increasing dominance of ageing is already apparent from just the mortality data. In a 2025 paper with Andrew Scott, we used a statistical approach to explain and predict how the mortality-age relationship has evolved over the last 100 years. Here we find that the key driver of life expectancy is now late-life mortality and that this dominance is likely to continue to increase. 

In more recent work, we look at this in a more holistic way, taking into account health and using the willingness to pay approach discussed above. We use a statistical clustering method applied to Global Burden of Disease data to group diseases not by their biology but by when in the life course they strike hardest. This produces four natural clusters: infant diseases, early adult diseases, late adult diseases, and the critical fourth group of ageing-related diseases. As shown in the chart below, ageing-related diseases are characterised by a burden that rises continuously with age.

Before thinking about this in monetary terms, we can look at the current burden of each of these disease categories purely in terms of health and mortality. To do this, we use the concept of Disability Adjusted Life Years (DALYs) – a way to estimate how much healthy life is lost because of diseases and injuries. The DALY cost of a given disease adds together Years of Life Lost (years lost when people die earlier than expected) and Years Lived with Disability (years lived with illness or disability that reduce health). The Table below shows how the current burden of all diseases are spread across our disease categories, both globally and separately for each group of countries by income.

The analysis so far has focused on welfare: how much people value longer, healthier lives in their own right. But the economic consequences of achieving healthy longevity extend further, and this is where my current research agenda is heading, supported by a VENI grant that I was recently awarded.

The central question is: as people live longer, what happens to work, productivity, and retirement? European policymakers are very concerned about this question, with fears that ageing populations and shrinking working-age cohorts will strain pension systems and labour markets across the continent. The extent to which this will manifest depends crucially on whether our longer lives are also healthier lives, and in what sense they are healthier. This is both a measurement challenge, as it is not clear what aspects of health are most relevant for people’s ability and inclination to work, and also a theoretical challenge as we need to consider how changes in health and longevity affect both the system as a whole and differences across individuals.

The increasing returns result we have established for health and welfare may well have a parallel in the labour market: the better we age, the more productive and engaged older workers can be, compounding the gains from further improvements in healthy longevity. Establishing whether that virtuous circle operates in the labour market is, I think, one of the most important questions in the economics of ageing for the decade ahead.

The story of the 20th century was one of remarkable progress, but the 21st century presents a different challenge, and a different opportunity. As the gains from conquering early-life diseases have been banked, the frontier of health has moved to ageing. Our research suggests that the more progress we make there, the more valuable each further step becomes. Understanding and acting on this virtuous circle may be the defining health challenge of the decades ahead.