This paper employs unit root tests that allow for two endogenously determined structural breaks to study whether or not invention activities are converging across U.S. regions/states. Using U.S. patent data from 1929 to 1997, we find technological beta convergence in six of the nine Census...

Determining whether per capita output can be characterized by a stochastic trend is complicated by the fact that infrequent breaks in trend can bias standard unit root tests towards non-rejection of the unit root hypothesis. The bulk of the existing literature has focused on the application of...

Determining whether per capita output can be characterized by a stochastic trend is complicated by the fact that infrequent breaks in trend can bias standard unit root tests towards non-rejection of the unit root hypothesis. The bulk of the existing literature has focused on the application of...