Welfare‐Increasing Monopolization*
研究了垄断化提高社会福利的条件，发现当垄断者向垄断者销售时（存在双重加价），社会福利可能高于竞争行业向效率不同的下游古诺寡头销售时的水平，这要求需求函数足够凹。
The conditions for monopolization to be good for social welfare are examined. Social welfare can be higher when a monopoly sells to a monopoly, with double margins, than when a competitive industry sells to a downstream Cournot oligopoly with differing efficiency levels. This requires inverse demand to be sufficiently concave, and cannot hold when demand is convex. When there are no vertical issues conditions are found for elimination of an inefficient firm to raise welfare, building on Lahiri and Ono (1988). In general greater demand concavity increases the relative importance of the benefit of redistributing output to the efficient firm.