Stagnation and innovation before agriculture

During the roughly 190,000 years between the emergence of anatomically modern humans and the transition to agriculture, sustained economic progress was rare. Although there were important innovations in the Upper Paleolithic, evidence from paleodemography indicates that population densities were driven more by climatic conditions than by technological innovations in food acquisition. We develop a model in which technological knowledge is subject to mutation and selection across generations. In a static environment, long run stagnation is the norm. However, climate shocks can induce experimentation with latent resources. This generates punctuated equilibria with greater technical capabilities and higher population densities at successive plateaus. The model is consistent with archaeological data on climate, population, diet, and technology from the Upper Paleolithic through the early Neolithic.