Diversified firms: existence and behaviors
提出一个微观基础理论解释多元化企业为何存在：它们能更好地部署因签约成本高而难以分割交易的生产要素，并进入这些要素比市场替代方案更高效的行业。
Abstract We propose a micro-founded theory of diversified firms. The theory suggests that diversified firms exist because they allow better deployment of factors that, because of sub-additive contracting costs, are hard to trade in fractions. Firms diversify into industries in which these factors are more productive than any alternatives available in the factor market. Like markets, diversified firms allow specialization by enabling factors to be used on a larger scale. The individual businesses making up a diversified firm exhibit specific similarities in behavior.