Preemptive Search and R&D Clustering
研究企业研发方向的选择，发现即使技术前景相同、专利独占且无信息外溢，企业仍可能扎堆研发同一技术，该结论也适用于其他排他性机会的竞争场景。
While many preceding studies discuss the equilibrium intensity of R&D, this article focuses on its equilibrium direction. There can be a pure-strategy equilibrium in which multiple firms cluster, i.e., attempt to develop the same technology even if (i) potential technologies are ex ante equally promising, (ii) each technology can be patented by no more than one firm, and (iii) there are no informational spillovers among firms. Economic applications of this clustering result are not confined to R&D. Any situation where agents are racing in search of exclusive economic opportunities can be an example of this model.