2017年诺贝尔经济学家得主Richard H. Thaler的学术成长史
这篇书评可能有关键情节透露
本书实际上是Thaler的学术自传。他的核心思想包括“心理账户”和“自我控制”理论。行为经济学理论没有大量的模型和演算,即使非专业人士理解起来也不会太费力。以下是一句话介绍他的核心理论基础。
1.心理账户(Mental Accounting): the psychology of spending, saving, and other household financial behavior;
2.自我控制(Self-control): choosing between now and later.
Thaler从传统经济学转向行为经济学的原因:
传统经济学的基础性矛盾(也是行为经济学逐渐从另类走向显学的原因):
The core premise of economic theory is that people choose by optimizing. Econs make choices are assumed to be unbiased.
Optimization+Equilibrium=Economics
Economists get in trouble when they make a highly specific prediction that depends explicitly on everyone being economically sophisticated.
行为经济学开始的基础:
The primary reason for adding Humans to economic theories is to improve the accuracy of the predictions made with those theories.
一些对Thaler有影响的思想:
1、Thomas Schelling “The Life You Save May Be Your Own”
统计学生命(statistical life)VS. 确定的生命(identified life)谁更值得救?
他的最大贡献是提出了一种衡量生命价值的观点,即一条生命的价值不光取决于与之相关的社会产出,还取决于人们为了防止死亡风险增加而愿意支付的代价.
2、机会成本 Opportunity costs: the opportunity cost of some activity is what you give up by doing it.
信用卡的案例:Paying a surcharge is out-of-pocket, whereas not receiving a discount is a “mere” opportunity cost.
3、禀赋效应 Endowment effect: people valued things that were already part of their endowment more highly than things that could be part of their endowment, that were available but not yet own.
4、沉没成本 Sunk cost: 沉没成本是指由于过去的决策已经发生了的,而不能由现在或将来的任何决策改变的成本。人们在决定是否去做一件事情的时候,不仅是看这件事对自己有没有好处,而且也看过去是不是已经在这件事情上有过投入。我们把这些已经发生不可收回的支出,如时间、金钱、精力等称为“沉没成本”(Sunk Cost)。
5、后视偏差 Hindsight bias: 即个体面临不确定性事件新的信息时,往往对先前获得的信息有过高的估价,进而在决策上发生偏差。
6、前景理论Prospect theory (Daniel Kahneman and Amos Tversky in 1979).: Prospect theory differs from expected utility theory in many fundamental ways. To begin with, it distinguishes two phases in the decision-making process: an editing phase, which is a preliminary analysis of the offered prospects, and an evaluation phase, which is when the prospect with the highest value is chosen from among the edited prospects.
百度了一下前景理论,写的比较复杂(看英文的介绍可能更清楚一点):前景理论是描述性范式的一个决策模型,它假设风险决策过程分为编辑和评价两个过程。在编辑阶段,个体凭借“框架”(frame)、参照点(reference point)等采集和处理信息,在评价阶段依赖价值函数(value function)和主观概率的权重函数(weighting function)对信息予以判断。简言之,人在面临获利时,不愿冒风险;而在面临损失时,人人都成了冒险家。而损失和获利是相对于参照点而言的,改变评价事物时的参照点,就会改变对风险的态度。
前景理论引申出的三个基本结论: 1,大多数人在面临获利的时候是风险规避的; 2,大多数人在面临损失的时候是风险喜好的; 3,大多数人对得失的判断往往根据参考点决定
7、Just Noticeable Difference: 指刚刚能引起差别感觉的刺激的最小差异量。
8、慢直觉 Slow hunch (Steven Johnson): not one of those “aha” insights when everything becomes clear. Instead, it is more of a vague impression that there is something interesting going on, and an intuition that there could be something important lurking not far away.
心理账户(Mental Accounting)
1、 获得效用和交易效用
对单一产品的整体效用包括acquisition utility(获得效用)和transaction utility(交易效用)。
获得效用:类似于经济学里的“消费者剩余”。获得效用影响消费者的购买决策行为,交易效用影响消费者的购买意愿:心理价格和实际价格的差别。例子:人们更愿意支付更高的价格用于购买旅游景点的饮料。
2、 沉没成本(sunk cost):过去已经花掉的钱对现在的行为造成的影响。亚马逊的Prime会员。
3、不同账户:根据传统经济学理论的可替代性,这些账户的划分都是毫无意义的。然而,事实却是它们确实存在而且对人们的消费行为有着重要的影响。
(1)消费被划分到不同的类别中:比如食品账户、居住开销账户等。
(2)财富被分配到不同的类别中:比如支票账户、储蓄账户、养老账户等。
(3)收入被划分到不同的类别中:比如日常的工资账户、意外之财账户中。