Matthew Baker is an Associate Professor of Economics at Hunter College and The Gradiate Center, CUNY.
Abstract: A commonly-used tool in explaining the origins, geographical dispersion, and degree of relatedness between cultures is the Age-Area Hypothesis developed by Sapir (1916). The hypothesis posits that the origin point of a group of related cultures or a linguistic stock is most likely where the languages comprising the stock are most divergent. While compelling and often-corroborated, the Age-Area Hypothesis has never been founded in basic principles, and this lack of structure limits its use. I describe a micro-founded model of the Age-Area Hypothesis based on mass migration, develop a measure of divergence between cultures based on phylogenetic trees, and develop an Age-Area Theorem. The model allows computation of probabilities that different locations are the origin points for the constituents of a group of related cultures. The model also provides a probabilistic explanation of Occam’s razor: migratory paths explaining the geographical dispersion of related cultures that are simpler are more likely. The paper concludes with applications to the origins of the Na-Dene and Afro-Asiatic Ethno-linguistic groups.