Purposive Diversification of R & D in Manufacturing
研究发现美国大型制造企业的研发多元化是有目的的，利用不同研究活动的互补性形成相关行业类别组，且这类企业将更多研发资金分配给专有性条件好的行业类别。
The R & D diversification in manufacturing of large US firms is found to be purposive, exploiting complementarities of various research activities and forming groups of related industry categories. Purposively diversified firms are seen to behave differently than randomly diversified or undiversified firms. Further, the behavioral differences between purposively diversified firms and others result because the former allocate relatively more R & D funds to industry categories where appropriability conditions are good and relatively fewer funds to those categories where appropriation of the returns from R&D is difficult. Finally, R&D expenditure and productivity are more closely linked at the group level than at the industry-category level, suggesting knowledge spills across industry categories are important.