如果你是其中的拍卖者 你会怎么样选择呢?
苏比克的美元拍卖:一张美元纸币被当众拍卖,规则有2:
纸币归报价最高者,新报价必须高于上一报价至少一美分,在规定时限内没有新报价则拍卖结束;
拍出第二高价者也要付出他最后一次报价的款项,但是什么也得不到。
[此贴子已经被作者于2006-12-17 14:01:55编辑过]
SHUBIK'S DOLLAR AUCTIONIn their free time, Martin Shubik and colleagues at RAND and Princeton tried to devise new and unusual games. According to Shubik, the central question was, "Can we get certain pathological phenomena as well-defined games?" They wanted games you could actually play. "I don't believe any game that can't be played as a parlor game," Shubik told me. In 1950, Shubik, John Nash, Lloyd Shapley, and Melvin Hausner invented a game called "so long sucker." This is a vicious game, played with poker chips, where players have to forge alliances with other players but usually have to betray them to win. When tried out at parties, people took the game seriously. ("We had married couples going home in separate cabs," Shubik recalls.) Shubik posed the question of whether it was possible to incorporate addiction in a game. This question lead to the dollar auction. Shubik is uncertain who thought of the game first or whether it was a collaboration. In any case, Shubik published it in 1971 and is generally credited as the game's inventor. In his 1971 paper, Shubik describes the dollar auction as an "extremely simple, highly amusing and instructive parlor game." A dollar bill is auctioned with these two rules: 1. (As in any auction) the dollar bill goes to the highest bidder, who pays whatever the high bid was. Each new bid has to be higher than the current high bid, and the game ends when there is no new bid within a specified time limit. 2. (Unlike at Sotheby's!) the second-highest bidder also has to pay the amount of his last bid – and gets nothing in return. You really don't want to be the second-highest bidder. Shubik wrote, "A large crowd is desirable. Furthermore, experience has indicated that the best time is during a party when spirits are high and the propensity to calculate does not settle in until at least two bids have been made." Shubik's two rules swiftly lead to madness. "Do I hear 10 cents?" asks the auctioneer – "5 cents?" Well, it's a dollar bill, and anyone can have it for a penny. So someone says 1 cent. The auctioneer accepts the bid. Now anyone can have the dollar bill for 2 cents. That's still better than the rate Chase Manhattan gives you, so someone says 2 cents. It would be crazy not to. The second bid puts the first bidder in the uncomfortable position of being the second-highest bidder. Should the bidding stop now, he would be charged 1 cent for nothing. So this person has particular reason to make a new bid – "3 cents." And so on Maybe you're way ahead of me. You might think that the bill will finally go for the full price of $1.00 – a sad comment on greed, that no one got a bargain. If so, you'd be way too optimistic. Eventually someone does bid $1.00. That leaves someone else with a second-highest bid of 99 cents or less. If the bidding stops at $1.00, the underbidder is in the hole for as much as 99 cents. So this person has incentive to bid $1.01 for the dollar bill. Provided he wins, he would be out only a penny (for paying $1.01 for a dollar bill). That's better than losing 99 cents. That leads the $1.00 bidder to top that bid. Shubik wrote, "There is a pause and hesitation in the group as the bid goes through the one dollar barrier. From then on, there is a duel with bursts of speed until tension builds, bidding then slows and finally peters out." No matter what the stage of the bidding, the second-highest bidder can improve his position by almost a dollar by barely topping the current high bid. Yet the predicament of the second-highest bidder gets worse and worse! This peculiar game leads to a bad case of buyer's remorse. The highest bidder pays far more than a dollar for a dollar, and the second-highest bidder pays far more than a dollar for nothing. Computer scientist Marvin Minsky learned of the game and popularized it at MIT. Shubik reported: "Experience with the game has shown that it is possible to 'sell' a dollar bill for considerably more than a dollar. A total of payments between three and five dollars is not uncommon." Possibly W. C. Fields said it best: "If at first you don't succeed, try, try again. Then quit. No use being a damn fool about it." Shubik's dollar auction demonstrates the difficulty of using von Neumann and Morgenstern's game theory in certain situations. The dollar auction game is conceptually simple and contains no surprise features or hidden information. It ought to be a "textbook case" of game theory. It ought to be a profitable game, too. The game dangles a potential profit of up to a dollar in front of the bidders, and that profit is no illusion. Besides, no one is forced to make a bid. Surely a rational player can't lose. The players who bid up a dollar to many times its value must be acting "irrationally." It is more difficult to decide where they go wrong. Maybe the problem is that there is no obvious place to draw the line between a rational bid and an irrational one. Shubik wrote of the dollar auction that "a game theory analysis alone will probably never be adequate to explain such a process." |
| William Poundstone, Prisoner's Dilemma, Doubleday, NY 1992, pp. 280-282. |
[此贴子已经被作者于2006-12-17 14:24:53编辑过]
如果你是其中的拍卖者 你会怎么样选择呢?
苏比克的美元拍卖:一张美元纸币被当众拍卖,规则有2:
纸币归报价最高者,新报价必须高于上一报价至少一美分,在规定时限内没有新报价则拍卖结束;
拍出第二高价者也要付出他最后一次报价的款项,但是什么也得不到。
对上述问题,做二种可以说是等价的变形:
一、现在做一个用人民币竞买1美元的游戏,假定1美元=10元人民币=1000分。
规则是:1、出价最高者,无偿得之。2、喊出次高价格者,要无偿付出自己所报数量的人民币。3、以1分人民币为最低喊价单位。
二、现在拍卖一个奖杯(任意的奖杯,例如可以是出土的金杯,可以是普通纸杯,可以是被用作官方世界杯的普通纸杯)。
规则:1、出钱最高者得之。2、出价次高者得无偿支付等于喊价的钞票。3、以1元为最低喊价单位。
[此贴子已经被作者于2006-12-27 16:58:42编辑过]
转:
苏比克的美元拍卖:一张美元纸币被当众拍卖,规则有2:纸币归报价最高者,新报价必须高于上一报价至少一美分,在规定时限内没有新报价则拍卖结束;拍出第二高价者也要付出他最后一次报价的款项,但是什么也得不到。实验证明,总支付在三至五美元之间是非常普通的一件事,因为停止竞拍就是允许自己被欺诈。天空中一些神秘的星球(超新星)突然变得极亮极亮,然后很快变成天空中的灰烬,这也许是其他星系中有感知能力的生物已经达到了他们所具有的科学知识的极限,由于没能解决如何共同存在下去这个问题,至少他们通过宇宙集体自杀而成功实现了一致。苏比克的美元拍卖正是我们这个核时代的真实写照,正所谓“道高一尺,魔高一丈”。其他生活中的实例还包括:无法下决心挂掉无人接听的电话;在公园里耐心地等待了几十分钟就为了玩几十秒钟的过山车;在电视机前即使看了一部很不好看的电影也会继续看下去直到结局,更别说每隔五分钟还要出现商业广告;修理一部又老又旧的汽车;再多打几圈牌以挽回损失;在等公共汽车时总想再等几分钟,最后还是决定放弃而招呼一辆出租汽车;在不满意的职业或不幸福的婚姻中虚度时光。
如果那“一美元”(严格说即拍卖的标的)不是一个“固定不变的东西”(并且这一点成为了common knowledge),这种类比还有原先的意义吗?
按老兄的意思,兄弟对问题做了变形,在上面,请看。
直接报99美分
兄弟觉着,这个问题就是解释价格形成和计算理想价格的问题。简单来说,是得出价格的一个问题:在一定的假设下,我们知道一定的信息,那么,多大的数目,才是那个所谓应当的合理的价格?
这个问题,也可以看成是抓次高者的游戏,看大家当中,谁是那个出价次高者,谁被抓住。
而由于最低喊价单位是1分、1美分,因此,出价最高者只要比次高者多拿出1分钱,就可以获胜了,进而,我们可以把出价次高者和出价最高者,看成是同样的价格了。所以,我们所抓到的那个出价次高者,他喊出的那个价格,恰恰正是我们要寻找的那个理想价格了。
SHUBIK'S DOLLAR AUCTION |
| William Poundstone, Prisoner's Dilemma, Doubleday, NY 1992, pp. 280-282. |
是这样,所以,那1美元,相当于任何商品,例如相当于天价的钻石。但是,人们不可能有无限的货币,如果人人都有一万亿以上的美元,就相当于人人只有十美元了。现实当中,人们的钱是有限的。
那么,在一定限制下,知道了具体的数量,如何计算理想的价格呢?如何抓到那个次高出价?
仅仅买卖1美元,是一种简单简化的情况,容易得出价格。如果市场上有多人、多种、大量货物去面对多人、大量的货币,就需要计算了。
[此贴子已经被作者于2006-12-27 19:42:05编辑过]
无底洞,还是报零吧。呵呵,确实任何一个大于零的数都存在风险,会有一股力把你吸引进去的。
我们可以把那1美元,看成是食物、饮用水、钻石、荣誉、浪漫等等,就是有足够吸引力的东西,是有足够需要的东西。
问题是,报价第二高者都必须付费吗?
为什么?“理想”的标准何在?
同样可以说,类比,也不是无原则的。
问题是,报价第二高者都必须付费吗?
报价第二高者,在现实当中不需要付费。例如用一个简单而明显的例子来说,拍卖一粒有名的钻石,那么,出价最高者获取了,第二高的人和其余的人就没有竞争到,但也不用付费(不考虑参加拍卖会的费用)。
从理论上来说,报价最高者-----即竞买获胜者,仅仅只需要比次高者多付出1分钱,就能竞争到那名贵钻石的(当然,现实当中,这种拍卖会有着规定或惯例,每次出价不可能1分钱,例如是要比上一报价至少高出1万元以上)。这样看来,我们可以把成交价(最高的报价),与次高的报价,可以看成是等同的了。
其实价格的位置,就是由那个次高来决定的。再按上述拍卖钻石这种例子来说,买到钻石的那个人,可能扛去了1000万元(既然带来了,一般来说,显然就准备好了要付出这么多了,不然也就不带来了),而报价次高者可能抱去了800万元,另外还有若干人带去了若干元。当开始拍卖后,随着竞争的进行,最后,报价报到了750万元了,在这时候,有800万元的人可能就知难而退了,或者呢,他还要搏上一博,则就喊出790万元(或者是由那1000万元的人喊出的),接着,就没有人会报价了-------除了那有了1000万元的人,这人就喊出了798万元试探一下,获胜。换句话说,拍卖的成交价格,不会接近1000万元的------虽然,这获胜者从效用等上面来评价,那钻石值1000万元。
假若,上述拍卖会当中,第二有钱的人,仅仅带去了300万元(而那个会准备1000万元的人,由于他了解其他大款的大体情况,就可能只带上500万元了-----这时候,这500万元者,如果按主流经济学的有关理论,又会如何思维与评价呢?),那么,拍卖的成交价格会很接近300万元的,不再会是750万元、798万元、801、810万元等等了。
其实那个次高者,虽然不用付费,但也有损失的:精神损失,等,例如说,他老婆会不高兴,他会失望,他会因此失去一个结婚对象进而贸易机会,等等。游戏当中规定了次高者也要付出,体现了这种损失吧。
至于游戏当中规定了次高者也要付出,并且无偿付出,那是为了增加游戏的趣味性吧,同时也符合真实的现实的情况:例如钻石拍卖会上的情况------价格的位置、水平由次高者“决定”,同时也体现了次高者也有竞买不胜之损失。
[此贴子已经被作者于2006-12-28 19:58:42编辑过]
为什么?“理想”的标准何在?
理想,就是理想情况的那理想。理想价格,或者说,就是理论价格。
另外,就这个游戏来说,一个明显有钱的人,凭对现场参与人员的大体估计,就可以使这个游戏失效的。例如说,他经过简单观察,发现参与人员都是熟人,而他们都不可能比他带了更多的现金(或者说,此时现场上,他们比他有钱的可能性是很小的,并且由于事发突然等等,不存在欺骗、合伙欺骗、开玩笑等可能),那么,他可以直接喊出一个无人应答的价格,例如是1000元现金。这时候,就不可能(或者可能性很小)有人再出更高报价了。因此这会是唯一的报价。
那么,此游戏就无法进行了,并且按此游戏的规则(报价次高者也要无偿付出,但,这时候却没有次高者了),是无法处理的。
其实这个游戏,不需要任何策略。
假定大家都很有参与热情(这种假设,是可以有各种现实情况支持的)。那么,在这种假设下,大家肯定会竞争到底的,也就是会把身上所有的现金都投入到拍卖当中去,直到有人穷尽。最后结果,肯定是钱最多的人获胜。因此说,也就不需要任何策略了,仅仅需要比谁的钱多。也因此说,这个游戏是缺乏学术价值的。
而这个游戏的特定内容(竞争1个美元,这是价值很小的东西,且这种拍卖是例如老师在教室、客厅对学生倡导进行的游戏,且次高者也要无偿付出,等等),限制了这种掏光身上一切现金之情况的出现。因此,这个游戏其实变成了心理、性格、意志等之比了-------不是关于策略的。
不过,我们能从这个游戏当中,产生2个疑问:
1、是否任何供求竞争------买方(很多人想买,分别有若干货币)之间竞买,卖方(很多人都卖类似货物,都很想卖,分别有若干货物)之间竞卖,买卖双方讨价还价(买方想价格低,卖方想价格高)------其产生的价格,都在某个次高上呢?
2、采取各种讨价还价策略,是能够成交的,会得到成交价格。不考虑任何策略,仅仅由货物数量、货币数量及其在人们中间的分布情况,也能计算出的理论价格。那么,这2种情况下得出的价格,是否相当接近呢?
从上述游戏,可以作出猜测:是,是的。
也就是说,任何成交价格,应当都是由某一次高的水平决定的,而无论采取任何竞争策略(不包括串通等等)最后的结果都相当接近于供求关系的状况。
计算出来的理论价格应当是最佳的-------假若各方各人都采取了最佳讨价还价策略的话,所得到的成交价格,就会非常接近理论价格。
又正如有人已经作出的结论:诚实往往是最好的策略。实力一直是最大的方法。
[此贴子已经被作者于2006-12-28 20:50:11编辑过]
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