ABSTRACT
Gregory Clark [40] points out that women over the course of their reproductive lives can give birth to twelve or more children, although prior to 1800, the number of children surviving to adulthood was always only a little over two, say 2.005. The world’s population growth rate before 1820 was small, averaging 0.01% between AD 1 and 1000, 0.1% between 1000 to 1500, and 0.27% between 1500 to 1820. Even given these small rates of population growth, the world’s population grew from around 100,000 in 130,000 BC to approximately 230 million in AD 1, to 1 billion in 1820 [132]. What mechanism kept the equilibrium growth rate at this low level?
