Unied growth theory predicts that the timing of the fertility transitionis a key determinant of contemporary comparative development, as itmarks the onset of the take-o to sustained growth. Neoclassical growth theorypresupposes a take-o, and explains comparative development by variationsin...

Conventional R&D-based growth theory suggests that productivitygrowth is positively correlated with population size or population growth,an implication which is hard to see in the data. Here we integrate R&D-basedgrowth into a unied growth setup with micro-founded fertility and...