Technological diversity is important to achieve long-term technological progress as diversity fosters recombinant innovation and renders undesirable lock-ins less likely. Many government policies influence the diversity of a technology, in particular by subsidizing collaborative innovation...

Empirical work suggests that the network of research and development alliances is asymmetric, with a small number of firms involved in the majority of partnerships. This paper relates the structure of the collaboration network to a fundamental characteristic of the demand for research output:...