Seminar in Microeconomics - Cédric Perret (University of Lausanne)

By expanding the value of what individuals produce, trade is recognized as driving the wide diversity of economic activities seen in human societies. Since productivity depends not only on occupational choices but also on innate abilities, we ask whether trade could have influenced human evolution, potentially generating genetic diversity. We model a system where individuals produce and exchange goods, using the Walrasian equilibrium framework, but considering that abilities to produce goods are determined by evolving genetic traits. Our analysis demonstrates that trade consistently promotes the maintenance of genetic diversity, favouring the coexistence of individuals with distinct traits. Additionally, we explore how genetic diversity and economic specialisation interact, particularly examining when one is necessary, sufficient, or just facilitating the emergence of the other. Our findings suggest that exchange economies play a crucial role in fostering both biological and economic diversity, and offer insights into how a cultural phenomena, here economic systems, may have shaped human evolution.