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...

A rising competitive pressure for innovations comes along with an increasing number of companies and public research facilities that include external sources of information into the innovation process. This trend towards an open innovation process can be verified empirically. External R&D...