Abstract

In this paper, we consider a mixed oligopoly market in which a public firm and private firms compete, in particular, in which private entrants are allowed to enter a monopoly market by a public incumbent who maximizes social welfare. It has been widely believed that the public firm has advantage over private firms because the former who maximizes social welfare can charge a lower price than the latter who maximizes its own profit. However, in a Hotelling model of product differentiation, we obtain the results that both the public firm and private firms charge the same price in equilibrium, and more importantly, that the equilibrium prices may rise as a result of competition, thereby lowering the consumer surplus, if the transportation cost is high enough. We also show that if a private firm enters the market by choosing its own degree of differentiation, it will prefer neither maximum differentiation nor minimum differentiation in the case that the public incumbent is myopic in the sense that it cannot anticipate entry as well as in the case that it is far-sighted enough to anticipate entry. This draws an important policy implication in the market of Korean housing guarantee services.

摘要

在本文中，我们考虑了一个混合寡头垄断市场，在这个市场中，公共企业和私人企业相互竞争，特别是在这个市场中，私人进入者被允许最大化社会福利的公共在位者进入垄断市场。人们普遍认为，公共企业比私营企业具有优势，因为前者使社会福利最大化，可以比后者最大化自身利润收取更低的价格。然而，在产品差异化的霍特林模型中，我们得到了上市公司和私营公司在均衡时收取相同价格的结果，更重要的是，均衡价格可能由于竞争而上升，从而降低了消费者剩余，如果运输成本足够高。我们还表明，如果一家私营公司通过选择自己的差异化程度进入市场，那么在公共现任者是短视的情况下，它既不会选择最大差异化，也不会选择最小化差异化，因为它无法预期进入市场。如果有足够的远见，可以预见进入。这对韩国住房保障服务市场产生了重要的政策启示。