请教一道PP3的逻辑题~~

Some airlines allegedly reduce fares on certain routes to a level at which they lose money, in order to drive competitors off those routes. However, this method of eliminating competition cannot profitable in the long run. Once an airline successfuly implements this method, any attempt to recoup the earlier losses by charging high fares on that route for an extended period would only provide competitors with a better oportunity to undercut the airline's fares.

Which of the following, if ture, most seriously weakens the argument?

A. In some countries it is not illegal for a company to drive away competitors by selling a product below cost.

B. Airline executives generall believe that a company that once underpriced its fares to drive away competitors is very likely to do so again if new competitors emerge.

C. As part of promotions designed to attract new customers, airlines sometimes reduce their ticket price to below an economically sustainable level.

D. On deciding to stop serving particular routes, most airlines shift resources to other routes rather than reduce the size of their operations.

E. When airlines dramatically reduce their fares on a particular route, the total number of air passengers on that route increase greatly.

这道题答案是B，我可以理解。不过我觉得D也对啊。别的航空公司在停止某条航线的服务以后，就把资源转移到别的航线上了，这样他们也不会再回到最初的航线去竞争了。这样也可以weaken提干的argument啊。

请问D错在哪里呢？

The origial argument says that it is impossible to recoup the company's ealier loss by raising the fare higher, based on the fact that the competitors are going to cut their price. i.e., there will be competition.

B says otherwise: Airline executives generall believe that a company that once underpriced its fares to drive away competitors is very likely to do so again if new competitors emerge. i.e., no competition is possible in the long run.

Hence, B is right.

D is wrong b/c it is irrelevant.

B. Airline executives generall believe that a company that once underpriced its fares to drive away competitors is very likely to do so again if new competitors emerge.

关于降价，这个是可预测的，所以是必然成立的assumption

D. On deciding to stop serving particular routes, most airlines shift resources to other routes rather than reduce the size of their operations.

这个是我们假设的，并不是一定成立，most也说明了例外的存在。

B对是可以理解的。所有的executives都知道一旦这个company实施过降价策略来驱逐竞争者，在有新的竞争者出现的时候，这个公司极有可能再次实施降价策略。在信息完全的情况下，既然所有的excecutive都知道这一事实，他们就不会在这个公司提高价格以后再进入这条航线来与其竞争。那么recoup当然就是可行的。所以B是削弱。这种情况有点像逻辑问题中的帽子问题。

不过D我觉得也有点对。只是不如B削弱得那么厉害。而且不够直接。

4楼，人家问的不是assemption,而是weaken哦。。。我也不明白你是从哪个角度weaken我的。。。

我的意思就是说既然题目让weaken的argument的主要论点是：这个方法行不通，因为不能长期盈利，那就应该用它可以盈利来weaken啊。

那B说：降价--驱逐竞争者--抬价--竞争者降价排挤他--再降价，这样不能盈利，所以和题目中的argument意思一致，哪里weaken了？

而D说其他竞争者资源已转移，那不是不能再回来排挤他，这样就可以盈利了，不是削弱么？！

我的想法的flaw在哪里？？

引用5楼的话:既然所有的excecutive都知道这一事实，他们就不会在这个公司提高价格以后再进入这条航线来与其竞争

这句话运用了经济学中"囚徒困境"原理, 我赞同,但是...这好象是常识哦,怎么可以推逻辑题呢.

原题就是说在抬高价格的时候,这个公司还会再降价,如此循环,就不会盈利啊.

我晕啊~~