Corporate focus and stock returns
发现1980年代公司聚焦（专注主业）能提升股东财富，聚焦程度与股票回报正相关，而多元化公司未能利用财务范围经济，且在并购市场中更活跃。
Greater corporate focus is consistent with shareholder wealth maximization. Diseconomies of scope in the 1980s are confirmed by a trend towards focus or specialization, a positive relation between stock returns and focus increases, and the failure of diversified firms to exploit financial economies of scope (coinsurance of debt or reliance on internal capital markets). Large focused firms were less likely to be subject to hostile takeover attempts than were other firms, but diversified firms were distinguished in the 1980s mostly by being relatively active participants, as both buyers and sellers, in the market for corporate control.