送交者: mangolasi 于 2006-4-27, 14:29:06:
回答: 普通人基本上不关心概念，但我同意方没有写好这一篇 由 xj 于 2006-4-27, 13:35:29:
猴子的故事说明动物是只顾眼前，不管今后。随之应该引伸到人类，其实人也一样，今朝有酒今朝醉。
--Monkeys (and we human being as well) can think of the future perfectly while still making the same choice. The crux here is not "not thinking about the future", but even I perfectly worry about the future (hence 4-3 rather than 7-0 because usually--very common sense--utility of nothing to eat is minus infinity), I am still impatient.
这里面的关键是人对未来的价值会打一定的折扣，也就是Enlighten说的time discount.
更广泛地讲，人对价值的判断不是一个线性的函数，不是价值越高人就越喜欢，这里面有个折扣因子，也就是你说的beta.
--No. Beta simply means "未来的价值会打一定的折扣", and merely a time discount, nothing else. The nonlinearity on the value is written in the utility function itself, not in beta. To see this \beta*value is actually a linear function. So if there is no nonlinearity in your utility function, increasing the value by 1 unit will increse \beta*value by \beta unit--\beta is a CONSTANT! \beta doesn't indicate any nonlinearity!
这也就联系到边际效用问题，同一块钱，在不同的水平价值不一样。
至于赌博则是另外一个问题。这是危险规避（risk aversion）问题。
--No. They are the same. Risk attitude and nonlinearity in utility function(i.e. non constant marginal utility) are the same thing. Concave utility function leads to risk aversion. To see this, 同一块钱，在不同的水平价值不一样, meaning if I currently have $100, losing $1 meaning I have $99, while gaining $1 meaning I have $101. So the happiness of jumping from $99 too $100 (i.e. regretness of gambling at unfavorable gambling result) exceeds the unhappiness of from $101 to 100 (i.e. feeling lucky of gambling at favorable result).
这个危险规避确实是由心理学家提出，然后用到经济学上的.
--give me a break. Daniel Bernoulli and Pierre-Simon Laplace are spinning in their tombs.
但老方提到的“理性”是指按照传统的“趋利”模型应该做的。
--For a company, 利 might merely means profit, hence “趋利”means picking a bigger expected value. For an normal individual, “趋利” means picking the bigger expected satisfaction (I stop using the jargon "utility").