Compared to other regions, Europe and Central Asia are by far the oldest. Moreover, population aging is set to accelerate further over the coming decades as large segments turn old. Additionally, some countries such as Russia and certain Eastern European countries are facing a shrinkage of their population. Against this backdrop, this report investigates what stands in the way of societies reaping the full benefits of increased longevity-that is, longer lives and potentially prolonged payoffs from human capital-and what can help to mitigate the possible negative impacts of a smaller and older workforce. Beginning with a focus on demographic trends, the report puts the rapid decline in fertility and contrasting migration trends in the region in a historical perspective and looks forward to the varying paths that population change may follow in the region. Next, it examines the evidence on the likely impact of demographic change on growth and savings, the labor force, firm and economy-wide innovation, poverty and inequality, and intergenerational solidarity. Finally, the report goes beyond diagnostics and puts an emphasis on what we know regarding successful policy interventions, presenting evidence on what has and has not worked in the past.