The Macrogenoeconomics of Comparative Development

Oded Galor has pointed me to his forthcoming article with Quamrul Ashraf in The Journal of Economic Literature.

The Macrogenoeconomics of Comparative Development

A vibrant literature has emerged in recent years to explore the influences of human evolution and the genetic composition of populations on the comparative economic performance of societies, highlighting the roles played by the Neolithic Revolution and the prehistoric “out of Africa” migration of anatomically modern humans in generating worldwide variations in the composition of genetic traits across populations. The recent attempt by Nicholas Wade’s “A Troublesome Inheritance: Genes, Race and Human History” to expose the evolutionary origins of comparative economic development to a wider audience provides an opportunity to review this important literature in the context of his theory.

A couple of paragraphs from the introduction:

Wade advances a modified evolutionary theory of long-run economic development, based on regional variation in the intensity of positive selection of traits that are conducive to growth-enhancing institutions. His theory suggests that variation in the duration of selective pressures on genetic traits across regions form the basis of differences in social behaviors across racial groups, thereby shaping variations in the nature of institutions and, thus, the level of economic development across the globe. Although at the outset, the broad outline of this argument appears plausible and largely consistent with existing evolutionary theories of comparative development, there is currently no compelling evidence for supporting the actual mechanisms proposed by Wade. …

The two fundamental building blocks of Wade’s theory are rather speculative. In particular, his narrative relies on unsubstantiated selection mechanisms and on empirically unsupported conjectures regarding the determinants of institutional variation across societies. … Rather than subjecting his hypothesized mechanism to the scrutiny of evolutionary growth theory, Wade follows the speculative supposition of Clark (2007), merely positing that in historically densely populated regions of the world that were characterized by early statehood, there existed a class of rich elites, endowed with genetic traits (e.g., nonviolence, cooperation, and thrift) conducive to growth-enhancing institutions, whose evolutionary advantage increased the prevalence of these favorable traits in the populations of those regions over time. It is far from evident, however, that the traits emphasized by Wade necessarily generated higher incomes in a Malthusian environment and were, thus, necessarily favored by the forces of natural selection. Moreover, Wade provides no evidence on how variations across societies in their geographical setting or historical experience could have given rise to differential selective pressures on these traits and, thus, generated variation in the growth-promoting genetic makeup of their populations. Furthermore, there is currently little scientific consensus on the extent to which the key behavioral traits of nonviolence, cooperation, and thrift, as emphasized by Wade’s theory, are genetically determined.

The second building block of Wade’s theory that links genetic traits to institutions is equally speculative. In particular, there is little evidence to support the claim that the variation in institutions across societies is driven by differences in their endowment of specific genetic traits that might govern key social behaviors.