Contestability in the Presence of an Alternate Market: An Experimental Examination
通过实验检验了存在正利润替代市场时的可竞争性，发现突袭式进入仍会发生，且平均价格与零机会成本情况无显著差异；同时考察了价格增量限制和人类买家对市场结果的影响。
Most earlier experimental tests ofthe contestable market hypothesis assume a zero opportunity cost of entry. This design feature makes interpretation of results in terms of entry behavior problematic. The experimental study that I report tests contestability with addition of an alternate market that yields a positive profit with certainty. This safe haven operationalizes a positive opportunity cost of entry. Hit-and-run entry is observed in experiments. Adjusted mean prices are not significantly different from zero opportunity cost case. Two methodological questions are also examined. In one treatment, sellers' price offers are allowed only in $0.25 increments. The simplification of sellers' decision space makes collusive arrangements more probable. Secondly, market outcomes using human subject buyers are compared with outcomes from experiments with computer-simulated demand. The disciplining effect of human subject buyers results in market prices that converge to competitive levels more quickly. * The theory of contestable markets as presented by William Baumol in his 1981 address as outgoing president of American Economic Association has received considerable attention since its introduction. The thesis of contestability is that we can model a market that attains a competitive outcome without (large numbers) price-taking assumption. In perfectly contestable market envisioned by Baumol and others, we would observe efficient (competitive) price in equilibrium even with few or only one active seller. The threat of entry is disciplining force that sustains efficient price as an equilibrium. Previous experimental tests of contestable market hypothesis for natural monopoly case all include at least two active firms pricing in every period. The laboratory outcomes of these markets are indistinguishable from destructive that has historically concerned scholars (Sharkey, 1982). One can assert that competitive prices that result from these natural monopoly markets are due to cutthroat competition because that market is the only game in town. The study of contestable natural monopoly that I report allows subjects option of earning a normal rate of return in an alternate market. Thus, there is at least possibility that we can observe a single active seller choosing efficient price.