Conventional R&D-based growth theory argues that productivity growth is driven by population growth but the data suggest that the erstwhile positive correlation between population and productivity turned negative during the 20th century. In order to resolve this problem we integrate R&D-based...

Four explanations for secular stagnation are distinguished: a rise in global saving, slow population growth that makes investment less attractive, averse trends in technology and productivity growth, and a decline in the relative price of investment goods. A long view from economic history is...

We provide a quantitative theory of deflation and secular stagnation. In our lifecycle framework, an aging population puts persistent downward pressure on the price level, real interest rates, and output. A novel feature of our theory is that it also recognizes the reactions of government...