A decomposition of changes to participation rates of 55-to-74 year-olds between 2002 and 2017 based on an estimated equation attributes more than two thirds of the median increase (of 10.9 percentage points) to rising life expectancy and educational attainment. About 1 percentage point is attributable to changes in statutory retirement ages, although part of the reason these effects are not larger is that in most countries, statutory retirement ages have not kept pace with life expectancy. Although difficult to incorporate in the empirical framework, evidence of falling disability pension rolls and reduced sensitivity of old-age participation to the level of unemployment suggests that the tightening of alternative early retirement pathways through unemployment or disability schemes has been a major factor in the turnaround in the participation rate of older workers. Projections indicate that participation rates for 55-to-74 year-olds should keep rising through 2030, by 3.4 percentage points for the median country. Rising life expectancy and educational attainment are projected to make the largest contributions, more than compensating for the negative contribution of population ageing in most countries.