Corporate focus and stock returns

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.