快的还是便宜的？动态市场中的突破点
Quick or cheap? Breaking points in dynamic markets
摘要：
我们研究了双边市场，其中玩家随着时间的推移随机到达，并从一个连续的类型中抽取。匹配客户和提供者的成本各不相同，因此社会规划者面临两个相互竞争的目标：a）减少玩家在匹配之前的等待时间; b）形成有效的配对以降低匹配成本。我们表明，这样的市场的特点是一个快速或廉价的困境：在一个大类的分配假设，没有“免费的午餐”，即，不存在沿着两个目标同时最优的清算调度。我们进一步确定了一个独特的突破点，标志着一个鲜明的减少匹配成本相比，增加等待时间。概括这个模型，我们确定了两个制度：一个，没有免费的午餐存在;另一个，机会之窗打开，以实现免费的午餐。值得注意的是，贪婪调度在这种情况下从来都不是最优的。
英文摘要：
We examine two-sided markets where players arrive stochastically over time and are drawn from a continuum of types. The cost of matching a client and provider varies, so a social planner is faced with two contending objectives: a) to reduce players' waiting time before getting matched; and b) to form efficient pairs in order to reduce matching costs. We show that such markets are characterized by a quick-or-cheap dilemma: Under a large class of distributional assumptions, there is no 'free lunch', i.e., there exists no clearing schedule that is simultaneously optimal along both objectives. We further identify a unique breaking point signifying a stark reduction in matching cost contrasted by an increase in waiting time. Generalizing this model, we identify two regimes: one, where no free lunch exists; the other, where a window of opportunity opens to achieve a free lunch. Remarkably, greedy scheduling is never optimal in this setting.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
