Global Population Growth, Technology and Malthusian Constraints: A Quantitative Growth Theoretic Perspective

How much further will the global population expand, can all these extra mouths be fed, and what is the role in this story of economic growth? We study the interactions between global population, technological progress, per-capita income, demand for food and agricultural land expansion from 1960 to 2100. We structurally estimate a two-sector Schumpeterian growth model with endogenous fertility and finite agricultural land reserves, in which a manufacturing sector provides a consumption good and an agricultural sector provides food to sustain contemporaneous population. The model closely replicates 1960-2010 data on world population, GDP, productivity growth and crop land area, and we employ the model to make projections from 2010 to 2100. Results suggests a slowdown of technological progress, and, because it is the main driver of a transition to a regime with low population growth, significant population growth over the whole century. Global population is slightly below 10 billion by 2050, further growing to 12 billion by 2100. As population and per capita income grow, demand for agricultural output almost doubles over the century, but the land constraint does not bind because of capital investment and technological progress. This provides a first integrative view of future population development in the context of modern growth theory.