Readers with long memories may recall the brief, inglorious UK fuel shortage of a few weeks ago, which was mostly caused by the rush to refuel for fear the pumps would run dry. Some petrol stations imposed a limit on how much you could buy — say, £25 of fuel and no more. It seems sensible enough, but a friend of mine (an economist) suggested this was the opposite of what was really needed. A maximum purchase encouraged more visits and more queues. Instead, petrol stations should’ve imposed a minimum purchase: nobody was allowed to buy fuel if their tank was more than a quarter full.
记性好的读者可能记得几周前英国经历的短暂而不光彩的燃料短缺，它的主要原因是众人担心加油站会没油，因而一窝蜂跑去加油。一些加油站对顾客可以购买的数量设置了上限，例如25英镑的燃油。这似乎是明智的，但我的一位朋友（一位manbetx20客户端下载 学家）认为，这与真正需要采取的做法恰恰相反。设定一个购买上限，只会鼓励人们多次光顾加油站，加入排队的车流。相反，加油站应该规定一个最低购买资格门槛：不允许油箱内仍有四分之一以上燃油的人购买燃料。