Smrkolj, G. and Wagener, F. (2019). Research among copycats: R&D, spillovers, and feedback strategies International Journal of Industrial Organization, 65:82--120.

We study a stochastic dynamic game of process innovation in which firms can initiate and terminate R\&D efforts and production at different times. We discern the impact of knowledge spillovers on the investments in existing markets, as well as on the likely structure of newly forming markets, for all possible asymmetries in production costs between firms. While an increase in spillovers may improve the likelihood of a competitive market, it may at the same time reduce the level to which a technology is developed. We show that the effects of spillovers on investments and surpluses crucially depend on the stage of technology development considered. In particular, we show that high spillovers are not necessarily pro-competitive as they can make it harder for the laggard to catch up with the technology leader.