This paper examines the channels through which ageing will shape the main economic factors that in turn affect potential growth; identifies current policy settings that may in fact amplify the adverse impact of demographic trends; and sets out policy reforms that will work to temper the effects of ageing on growth. The paper begins with a brief discussion of demographic issues. The analysis first focuses on the impact of these trends on the future level and structure of consumption, which may affect aggregate saving and the structure of the economy, respectively. Then, it explores the main channels through which ageing affects the supply side of the economy following a production function approach: capital markets, labour markets and productivity. The empirical analysis focuses on a subset of large OECD countries with differing ageing patterns and generosity of pension systems. Using a simple general equilibrium overlapping generations model and considering alternative reform scenarios, some illustrative simulations are presented decomposing the effects of ageing on potential GDP per capita growth and economic convergence within OECD countries.