Essays on human evolution and economic growth

This thesis explores a series of dynamic models incorporating evolutionary and economic dynamics and demonstrates the contribution that an evolutionary approach can make to economics.

After assessing the extent to which economic thinkers have incorporated evolutionary theory into their analysis, we show that a simulation of the model developed in Galor and Moav [Galor, Oded and Omer Moav (2002) Natural selection and the origin of economic growth. Quarterly Journal of Economics 117(4), 1133–1191] resembles the period of Malthusian stagnation before the Industrial Revolution and the take-off into a modern growth era. We investigate the stability of the modern growth era and show the
economy can regress to a Malthusian state.

We then present an evolutionary theory of long-term economic growth in which the human ability to develop new ideas evolves over time. As more mutations occur in larger populations, population growth will increase the rate at which innovation-enhancing traits may emerge. Human evolution enhances population growth and it makes the population more robust to technological shocks. As the population grows, the scale effect of population size on the production of ideas becomes a relatively more important driver of technological progress than further increases in innovative potential.

In the following chapter, we propose the evolution by sexual selection of the male propensity to engage in conspicuous consumption contributed to modern rates of economic growth. We develop a model in which males engage in conspicuous consumption to send an honest signal of their quality to females. As males fund their conspicuous consumption through participation in the labour force, an increase in the prevalence of signalling males gives rise to an increase in economic activity.

Finally, we propose the recent rise in the fertility rate in developed countries may be the beginning of a broader increase in fertility towards above-replacement levels. Environmental shocks that reduced fertility over the past 200 years temporarily raised fertility heritability. As those with higher fertility are selected for, the “high-fertility genotypes” are expected to come to dominate the population. Even with low levels of genetically based variation in fertility, there can be a rapid return to a high-fertility state. In the longer term, this implies that the proportion of elderly in the population will be lower than projected.