Innovation processes within corporations increasingly tap into international technology sources, yet little is known about the relative contribution of different types of innovation channels. We investigate the effectiveness of different types of international technology sourcing activities...

We examine the "home bias" of international knowledge spillovers as measured by the speed of patent citations (i.e. knowledge spreads slowly over international boundaries). We present the first compelling econometric evidence that the geographical localization of knowledge spillovers has fallen...

Using new data on citations to university patents and scientific publications, we study how geography affects university knowledge spillovers. Citations to patents decline sharply with distance up to about 150 miles and are strongly constrained by state borders. Distance also constrains...