This thesis consists of five essays in the field of innovation economics, with an introductory chapter. The focus is mainly empirical with four of the five chapters consisting of studies of aspects of Swedish innovation activity. These empirical chapters are an endeavor to quantify aspects of the effects of the public-good property of knowledge. To this effect, innovation indicators were collected regarding industrial and firm research and development (R&D); regional indicators were collected using business and university R&D and records of patent applications and granted patents assigned to Swedish regions using the residential location of inventors.

The first essay studies the productive effect (total factor productivity) of R&D on Swedish firms and the effect that R&D can be expected to have on other firms. The second essay analyzes, with corporate groups as the unit of observation, the effect of accessibility to R&D in universities, and in other groups’ R&D on the innovative capability of the individual group. The third essay tries to characterize the extent to which Swedish regions are specialized or diverse. This is summarized in a single variable which is used to test the effect on innovative activity as measured by the number of patent applications. The fourth essay, the theoretical study of the thesis, constructs a two-region model with two firms residing in each. The incentives for doing process R&D are worked out by agglomerating consumers in one of the regions, and by changing interregional accessibility. The sixth essay studies Swedish inventor networks and regional affinity based on networks.