In the cross-country literature, cognitive skills are robust predictors of economic growth. We investigate claims by psychologists that the same is true at the state level. In a variety of specifications using four proxies for average state IQ used in the psychology literature, little evidence...

National measures of cognitive skill, including IQ tests, have received attention recently as a possible driver of cross-country productivity differences. In a parallel literature, national measures of entrepreneurial activity and pro-entrepreneurship policies have received similar attention....