Many countries will be confronted with ageing populations in the coming decades. This will crucially affect the economic outlook for the economy. Population changes directly affect the size of the labour force and consequently potential employment and output growth. In addition, changes in demographic trends strongly influence savings and investment behaviour, the outlook for the public finances, a range of financial market variables and, more controversially, may impact on the pace of productivity growth in an economy. Because the timing and magnitude of demographic changes varies...