We propose a unified growth theory to investigate the mechanics generating the economic and demographic transition, and the role of mortality differences for comparative development. The framework can replicate the quantitative patterns in historical time series data and in contemporaneous...

High-income countries have generally experienced falling fertility in recent decades. In most of these countries, the total fertility rate is now below the level that implies a stable population in the long run. This has led to concerns among economists, policymakers, and the wider public about...