Declining potential growth in OECD countries: An explanation by endogenous growth

We start with a traditional idea of endogenous growth: The growth rate depends positively on capital intensity (the capital/production ratio). The optimal capital accumulation behaviour is then changed, since it is useful to have more capital to increase growth. So how can we explain the slowdown in potential growth on the basis of this model? It may be due to: Obviously demographics (slower labour force growth), but also; Lower efficiency of capital to stimulate growth, which may be the case if the composition of capital is skewed at the expense of technological capital; A rise in the rate of wear and tear (obsolescence) of capital; An increase in the preference for the present (there is then more consumption and less capital accumulation). Evidence from OECD countries shows that the slowdown in potential growth can be explained by: Population ageing; An acceleration in the obsolescence of non-housing capital; An increase in preference for the present.