你在3楼说的那些东西我真的看不懂，太晦涩了，也与我所讨论的问题无关。我讨论的是最原始的一价定律。这也怪金融学的学风太野，概念都搞得乱七八糟，真不像个正经学科。

科学与宗教的本质区别就在于理论能够被实践所检验。

自然科学与社会科学都属于科学，是科学就要符合科学的做事原则。

而且把一个明显与事实相背的东西叫成“定律”已经不是科不科学的问题了，简直就是脑子有问题！

无套利不能保证一价，楼主犯的就是这个错误

哈哈，你终于想明白其中的道理了。我的目的已经达到了，既然你明白销售成本也会影响价格，你为什么还支持一价定律呢？一价定律里可没有提到销售成本啊!

或者说要想让一价定律成立，至少还应该加一个假设前提，“销售没有成本”。

但没有加这个前提假设的一价定律就是错的！

其实，要想让一价定律成立，还要加很多其它假设条件，我以后还会举其它例子，你慢慢就会明白。

我最终想说明的是，如果一价定律成立，那么世界就面目全非了。

[此贴子已经被作者于2009-5-14 15:14:56编辑过]

那么是否可以理解为“一价+交易费用”？

无套利+复制策略的存在性（包括交易费用可忽略）

Law of one price

From Wikipedia, the free encyclopedia

The law of one price is an economic law stated as: "In an efficient market all identical goods must have only one price." The law of one price relates to the outcome of free trade and globalization. It is the theory that some day all areas of the world will make the same amount of money as every other part of the world for equal work/product quality.

The intuition for this law is that all sellers will flock to the highest prevailing price, and all buyers to the lowest current market price. In an efficient market the convergence on one price is instant.

  An example: Financial markets

Commodities can be traded on financial markets, where there will be a single offer price, and bid price. Although there is a small spread between these two values the law of one price applies (to each). No trader will sell the commodity at a lower price than the market maker's offer-level or buy at a higher price than the market maker's bid-level. In either case moving away from the prevailing price would either leave no takers, or be charity.

In the derivatives market the law applies to financial instruments which appear different, but which resolve to the same set of cash flows; see Rational pricing. Thus:

  Where the law does not apply

• The law does not apply intertemporally, so prices for the same item can be different at different times in one market. The application of the law to financial markets in the example above is obscured by the fact that the market maker's prices are continually moving in liquid markets. However, at the moment each trade is executed, the law is in force (it would normally be against exchange rules to break it).
• The law also need not apply if buyers have less than perfect information about where to find the lowest price. In this case, sellers face a tradeoff between the frequency and the profitability of their sales. That is, firms may be indifferent between posting a high price (thus selling infrequently, because most consumers will search for a lower one) and a low price (at which they will sell more often, but earn less profit per sale).^[1]
    
• The Balassa-Samuelson effect argues that the law of one price is not applicable to all goods internationally, because some goods are not tradable. It argues that the consumption may be cheaper in some countries than others, because nontradables (especially land and labor) are cheaper in less developed countries. This can make a typical consumption basket cheaper in a less developed country, even if some goods in that basket have their prices equalized by international trade.

  Apparent violations

• The best-known example of an apparent violation of the law was Royal Dutch / Shell shares. After merging in 1907, holders of Royal Dutch Petroleum (traded in Amsterdam) and Shell Transport shares (traded in London) were entitled to 60% and 40% respectively of all future profits. Royal Dutch shares should therefore automatically have been priced at 50% more than Shell shares. However, they diverged from this by up to 15%.^[2] This discrepancy disappeared with their final merger in 2005.

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麻烦你再仔细看看解释，什么是一价定律，然后动动你的脑子，不要再在这里大言不惭~~~

[此贴子已经被作者于2009-5-15 13:50:35编辑过]

通过王府井的这个例子，我们应该悟出一个道理，真正驱动真实世界的价格趋于均衡（均衡是指各地的价格趋于稳定，而不是趋于一价）的动力不是什么一价定律，而是利润率趋同原理。

也就是说为什么王府＃地区的价格稳定在5元而其它地区稳定在3元，是应为两地销售商的利润率是大致相同的。如果某地的利润率偏高，就会引来销售商迁移，从而影响价格，最终使各地的利润率大致趋同。

一价定律只可能在面目全非的虚幻世界里成立，在真实的世界里，一价定律和利润率趋同原理根本就是矛盾的，怎么可能成立呢？

你在卖5元的门口竖块招牌卖3块，然后运足够量的饮料过来，你看看最终会不会5块的也卖3块？？随便豆腐干的文章还好意思发出来，跟你解释你也不听。还好意思正儿八经的取个什么圣弈投资 。。。。

请你仔细思考一下你的设想是否可行？

不要性口雌黄嘛。

你也知道这个想法不可行啊，那是不是就是说明存在贸易壁垒这种阻碍呢？？但金融市场这种阻碍相当小，这种显然明显存在的套利空间一下子就会被消除。你举得例子看似有力度，其实是在诡辩~~~~

[此贴子已经被作者于2009-5-15 14:52:54编辑过]

应该说他的假设还不够多，没有排除更多的情形，不过，这些例外不是经济学要研究的内容。

应该是管理研究的东西，你知道市场营销的4P’s吗，解释王府井的饮料比别的地贵就是市场营销里4P’s

中的Place，地方不一样价格就是不一样，因为各个地方对商品价格的敏感性是不一样的。

科学界也有很多与事实相背的定律，牛顿运动定律是真理吗，爱因斯坦把他否定了，那爱因斯坦的相对论是真理吗，事实上现在已经出现很多相对论的反对之声。

但是！但是！这并不妨碍一门学科向前发展，相反，这些都是发展过程中的阶段性成果。

同样经济金融学界也是一样，我也认为，经济学家多少有些完美主义，也许，这正是一种科研需要的概括能力。

什么是科学，恩格斯说，科学的本质就是数学。所以我觉得，只要能成功的运用了数学的就是科学，这门学科也才能真正得到发展。

恩格斯算什么东西？竟然还有人把恩格斯的话当真理。

牛顿定律当然是真理，如果你上过高中话，应该做过验证牛顿第二定律的实验。能被实践验证的就是真理啊。

当然，我们一般意义上说的真理都是相对真理，即使是相对真理也要符合真实世界，可以被事实验证。

相对论、量子力学也是相对真理。不能简单地说相对论就是对的，牛顿力学就是错的。

关键是你们承不承认“利润率趋同原理”，如果承认的话怎么还可以承认“一价定律”呢？

科学不可以如此自相矛盾！

我是金融本科生，刚刚接触金融学！处在概念的包围阶段。

   我想问一下楼主，你觉得“一价定律”是不是市场追求的最终效果？讨论一价定律是在完全竞争的市场，而这种状态我们达不到，但是对于研究还是有很大的价值的。我觉得这就跟“市场供求定律”一样，我们一直在追求市场达到一个供求平衡的状态，但实际的市场始终都达不到这种状态。在我们追求这种最终结果的时候，市场在不断完善，也不断在创造新的价值，人们在其中也不断获利。