Population ageing and potential growth

Population ageing mechanically reduces potential growth, as the working-age population grows less fast or declines. But does it also reduce potential growth by slowing productivity gains? We can imagine two mechanisms that would work in this direction: The employed population becomes older on average and therefore less productiv e ; Population ageing leads to an increase in spending on pensions and healthcare, and therefore in the tax burden, which discourages investment and curbs productivity. We compare OECD countries to see whether these two mechanisms weakening productivity gains can be observed. The second mechanism (the effect of pension and healthcare spending) seems consistent with the facts.