Are knowledge spillovers international or intranational in scope? Microeconometric evidence from the US and Japan

In this paper, I provide new estimates of the relative impact of intranational and international knowledge spillovers on innovation and productivity at the firm level, using previously unexploited panel data from the U.S. and Japan. My estimates suggest that knowledge spillovers are primarily intranational in scope, providing empirical confirmation of an important assumption in much of the theoretical literature. The implications of this finding are discussed in the conclusion. (C) 2001 Elsevier Science B.V. All rights reserved.