This paper develops an innovation model where firms choose which research paths to follow. Contrary to most of the literature which focuses only on the level of investment in innovation, this model captures both the variety of research paths undertaken and the amount of duplication of research....

This paper develops a fairly general model of platform competition in media markets allowing viewers to use multiple platforms. This leads to a new form of competition between platforms, in which they do not steal viewers from each other, but affect the viewer composition and thereby the...