On the Existence of Cournot Equilibrium
证明在单一同质商品市场中，若每家企业的边际收益随其他企业总产出增加而下降（由凹性逆需求隐含），则古诺均衡存在，且不要求边际成本非递减或技术相同；同时给出反例说明条件不满足时均衡可能不存在。
This paper examines the existence of n-firm Cournot equilibrium in a market for a single homogeneous commodity. It proves that if each firm's marginal revenue declines as the aggregate output of other firms increases (which is implied by concave inverse demand) then a Cournot equilibrium exists, without assuming that firms have nondecreasing marginal cost or identical technologies. Also, if the marginal revenue condition fails at a "potential optimal output", there is a set of firms such that no Cournot equilibrium exists. The paper also contains an example of nonexistence with two nonidentical firms, each with constant returns to scale production.