第五章-管理策之二决策偏向-课件.ppt

1、Smart Leaders,Foolish Choices:Avoiding Decision Making TrapsLecturer:姬定中Department Of Business,NITAfter this lecture you will be able to knowlFraminglAvailabilitylRepresentativenesslAnchoring&AdjustmentlOverconfidence FraminglTendency to make different decisions depending on how a problem is present

2、edl边框效应（framing effect）是指由于问题表述的语境不同，对同一个问题的两种逻辑意义上相似的描述最终导致不同的决策判断的效应 4Framing Effect l甲店 現金100元 刷卡加5%l乙店 刷卡105元 現金扣5%Cash or Credit?$1.30/gal5 cent discountfor cash.$1.25/gal5 cent chargefor credit.Discount seems negligible,peopleuse credit card.Surcharge isoutrageouspeople pay cash.gainslossesExa

3、mple:framinglYou go to Shanghai and decide to go to a Shanghai Grand Theatre for a play.You buy a ticket for$100 in the morning,but when you go to the theater that evening,you discover you have lost the ticket.You have plenty of money to buy another one:do you?lYou go to Shanghai and decide to go to

4、 a Shanghai Grand Theatre for a play and tickets cost$100.You go to the theater that evening and when you start to pay for your ticket,you discover you have lost$100.You have plenty of money to buy a ticket:do you?有过看电影丢了票的经历吗？有过看电影丢了票的经历吗？l想象一下，你已经决定去看一场戏剧，每张票的价格是30 元。当你进入戏院买票时，你发现不知什么时候你丢了30 元。现在你

5、还愿意花30元钱去买票吗？（愿意）（不愿意）l想象一下，你已经决定去看一场戏剧，每张票的价格是30 元。当你进入戏院验票时，你发现你的票丢了。现在你愿意花30元钱重买一张票吗？（愿意）（不愿意）结果结果选择选择背景背景丢了钱丢票愿意愿意85（80%）64（60%）不愿意不愿意21（20%）42（40%）结果的解释结果的解释l买两张票时，我们很容易感到是花了60元看一场电影；l而掉了30元和买一张票时，掉的30元我们并不算做是看电影花的（另外单独做账了）。我们只不过是将丢失的现金归结为倒霉，仅仅使我们感到没有原来那么富有，而不会直接与看电影相关联。How you frame itlDe Mart

6、ino and his colleagues scanned the brains of 20 volunteers.At the same time,the researchers told the participants they received a sum of money and then repeatedly posed them one of two choices:Keep a chunk of money or gamble,or lose a chunk of money or gamble.lAs expected,those told they could keep

7、money or gamble were generally leerier of risk.On the other hand,volunteers informed they could lose money or gamble often were more risk-seeking.Framing EffectslRefers to how decision-makers view a problem from a win-loss perspective.lThe way a problem is framed often influences choices in irration

8、al wayslSuppose youve been given$1000 and must choose between:A.Receive$500 more immediatelyB.Flip a coin and receive$1000 more if heads occurs or$0 more if tails occursFraming Effects(cont)lNow suppose youve been given$2000 and must choose between:A.Give back$500 immediatelyB.Flip a coin and give b

9、ack$0 if heads occurs or give back$1000 if tails occursInitial state$1,500Heads(50%)Tails(50%)$2,000$1,000Alternative AAlternative B(Flip coin)Payoffs说明说明我们我们l面对获利时，是风险厌恶者；l面对损失时，是风险追求者。赢了一点就跑，输了许多却还不愿认输。继续思考：那人又为什么买6合彩啊？实验研究表明实验研究表明丢掉10元钱所带来的不愉快感受比捡到10元所带来的愉悦感受要强烈得多。“损失损失10元钱元钱”和和“获益获益10元钱元钱”所带来的感受

10、是不一样的所带来的感受是不一样的别人的好处是我们难以感受到的，别人的不好却是让我们深感痛苦的。“损失损失10元钱元钱”和和“获益获益10元钱元钱”所带来的感受是不一样的所带来的感受是不一样的所以，孔夫子提醒我们，滴水之恩，当涌泉相报但但丢掉10元钱所带来的不愉快感受比捡到10元所带来的愉悦感受要强烈得多。一定如此吗？呵呵呵呵上面介绍的研究表明，我们是风险追求者还是风险厌恶者，与许多因素有关：l是面对盈利，还是亏损；l预期的是收益，还是亏损；l刚刚是赌赢了，还是赌输了；l是男的，还是女的；l这一点还与偏执与否及程度有关面对收益真是风险厌恶者吗？面对收益真是风险厌恶者吗？是风险厌恶者还是风险追求者

11、，还决定于概率的大小：获利的概率太小时，人们也更多地成为风险追求者。所以我们会买6合彩啊！所以所以我们是风险追求者还是风险厌恶者，与许多因素有关：l是面对盈利，还是亏损；l收益或亏损是否是预期的；l刚刚是赌赢了，还是赌输了；l是男的，还是女的；l收益或损失的概率是大还是小；l传统的设想人是理性的，没有系统的厌恶。可研究表明，这一切是变化的，而且是在不同层次上变化的。我们是稳定不变的吗？我们是稳定不变的吗？l我们有时喜欢赌，有时又不喜欢赌。l有时比较谨慎，有时又比较冒险，愿意“赌大的”。如何来评价本周如何来评价本周亏亏3000元？元？你可能想到的是：l哎，倒霉，亏了3000元！l嘿，上周还赚了1

12、0000元；本周只亏了3000元。为什么感受不一样啊！Framing(from Plous,1993)lWording issues in questionnairesDo you get headaches frequently?(2.2/wk)Do you get headaches occasionally?(0.7/wk)lSuggests that the way we frame problems or issues can have significant impact on the information we gather and on the decisions taken

13、(Hart)Framing(from Plous,1993)Overcoming framing effects:lEvaluate the quality of your assumptions and existing frames(appropriate?realistic?how do they direct your attention?)lSeek other opinions(e.g.people who continually disagree with you)lTemporarily adopt other peoples(petitors,employees,top ma

14、nagement)viewpoint,to see how they might be framing the situation可得性启发可得性启发请问：K在英文单词里，是更常出现在第一个字母位置，还是第三个字母位置？第三个字母位置是K的词是起首字母为K的词的三倍Availability HeuristicWe are biased by information:that is easier to recallvivid,well-publicized or recentmore salient(our attention is drawn to it)All of this makes i

15、t more available to us 所谓“可得性启发(availability heuristic)”，是说最易被想起的事件通常被认为最普遍。相应地人们对他们不易记忆的事物则认为是不常发生的。Availability Tendency to judge the likelihood of an occurrence on the basis of the extent to which other like instances can easily be recalled.lEx.Are there more words beginning with“R,”or having“R”a

16、s third letter?lMost will say beginning,simply b/c it is easier to think of examples for this possibilitylActually more words with an“R”as third letterVividnesslVividness:how concrete or imaginable something is,or how emotionally stimulating(Hart&Bing)lExample from a drunk-driving trial simulation“O

17、n his way out the door,Smith staggered against a serving table,knocking a bowl to the floor.”“On his way out the door,Smith staggered against a serving table,knocking a bowl of salsa dip to the floor and splattering tomato salsa on the white carpet.”18 hours later,significantly more subjects given t

18、he second scenario judged Smith to be guilty(remembered vivid information more easily,based judgement on it)(Plaus,1993)Availability in uselEase of recall is often a good clue to likelihood of occurrence but not always.lBeware of information that comes too easily to mind(because it is vivid,salient,

19、recent)you might be overlooking something more subtle but crucial!问题问题l某女，31岁，单身，坦诚、非常聪明。专业哲学，在学生时代积极关心歧视问题和社会公平问题，同时参加了反核示威。l请回答，哪一个可能性更大：A:“该女是银行出纳员”；B:“该女是银行出纳员和女权运动者”。我们知道，男女比例大致相等我们知道，男女比例大致相等那么，那么，请估计请估计在有6个孩子的家庭中，男(B)女(G)儿童出生顺序为GBGBBG和BGBBBB的比例，哪个更高？（B代表男孩，G代表女孩）典型（代表）性启发典型（代表）性启发l某女，31岁，单身，坦

20、诚、非常聪明。专业哲学，在学生时代积极关心歧视问题和社会公平问题，同时参加了反核示威。l请快速回答，哪一个可能性更大：A:“该女是银行出纳员”；B:“该女是银行出纳员和女权运动者”。为什么那么多人选择了B呢？我们知道，男女比例大致相等我们知道，男女比例大致相等那么，那么，请估计请估计在有6个孩子的家庭中，男(B)女(G)儿童出生顺序为GBGBBG和BGBBBB（B代表男孩，G代表女孩）的比例，哪个高？结果大多数被试估计前者远高于后者。为什么会这样呢？要知道从机会来说，两者的概率应是相等的啊。就因为GBGBBG更典型也更有代表性：更能代表整个人口中的比例，而且看起来更随机。Representat

21、ivenesslRepresentativeness:Tendency to be overly influenced by stereotypes in making judgments about the likelihood of occurrences.lexample:Robert wears glasses,speaks quietly,and read a lot.Is it more likely that Robert is a librarian or a farmer?lMost will pick librarian,b/c(A)Roberts characterist

22、ics,are more consistent with a librarian(B)ExampleslYou flip a coin 6 times.Given that flipping a fair coin is random(a 50-50 chance or a head or tail).Which of the following outcomes is most likely or probable?A.HHTHTTB.HHHTTTlBoth are equally likely the probability is same on each toss.Representat

23、iveness we use this shortcut as a way to judge the degree to which an individual object,person or event is representative of a specific category,group,etc.The use of this heuristic typically means that we underuse the base rate information that may be availableRepresentativenesslSubjects were told t

24、hat personality tests had been done on a group consisting of 30 engineers and 70 lawyers.They were then given 5 short descriptions and told that these had been chosen at random from the 100.lHere is one such description:Is Jack a Lawyer or an Engineer?Jack is a 45 year-old man.He is married with thr

25、ee children.He is generally conservative,careful and ambitious.He shows little interest in political and social issues and spends his spare time on his hobbies.The subjects were then asked the following question:In your opinion,what is the probability that the person described is an engineer,on a sc

26、ale of 0 to 100?Example 2 the use of stereotypeslThere are 100 people in a room,70 of them are lawyers,30 are engineers.lBill is randomly selected from this room.What is the probability he is a lawyer?lDick is a 30-year-old man.He is married with no children.A man of high ability and high motivation

27、 he promises to be very successful.He is well liked by his colleagues.lJack is 45-years-old,and married with 3 children.He tends to be conservative,careful,and ambitious.He shows little interest in political and social interests,and enjoys carpentry,sailing,and mathematical puzzles.Representativenes

28、s:Insensitivity to probability base rateslK&T found that peoples ratings of whether Jack was an engineer were virtually unaffected by the base rate information(70%Lawyers or 30%Engineers)lThe more“engineer-specific”information was given(e.g.he likes carpentry,puzzles),the higher the probability rati

29、ngs that Jack was an engineer.lIn general,the more detail people are given,the more they ignore the base-ratesIgnoring Base RateslWhy do more hotel fires start on the 1st ten floors than the second ten floorslFrank is a meek and quiet man whose only hobby is playing chess.He was near the top of his

30、college class and majored in philosophy.Is he a librarian or a business man?lYouve watched a coin toss come up heads 5 times in a row.If you bet$100 on the next toss,would you choose heads or tails?Representativeness heuristic:ConclusionlSimilarity(analogy)&probability can be related,so representati

31、veness can be a good heuristic most of the time.lBut,like availability,it leads to systematic,predictable biases for certain tasks.lWe are flawed probability estimators,insensitive to base rates and sample sizes and easily influenced by detailed scenarios;we are poor estimators of outcomesThis affec

32、ts our choice of alternatives in decision makinglBut knowing this can help us avoid some of the pitfalls请请大致估计大致估计请把答案写在相应问题后面的（）内。请大致估计有多少非洲国家是联合国成员。这里要告诉你的是，肯定在1个以上。请大致估算请大致估算1x2x3x4x5x6x7x8请大致估计有多少非洲国家是联合国成员。这里要告诉你的是，肯定在100个以内。请大致估算请大致估算l8x7x6x5x4x3x2x1锚定与调整锚定与调整Anchoring&Adjustment 为什么在这两个小测验中，人

33、们的估计会因表述的稍许差别而极大地不同呢？是1与100（或1、2、3等前几个数)影响了人们的估计：人们的估计被锚定在最初的这样一个数附近。Anchoring&Adjustment(Tversky and Kahneman,1974)Tendency to be influenced by an initial figure,even when the information is largely irrelevant We judge size or quantity based on an initial anchor value plus an adjustmentStage 1:Pers

34、on starts with initial idea of answer(“anchor”)l“Ball park”(general)estimate.lAnchor may be suggested by perception,experience or by something in the environment.Stage 2;Person adjusts away from initial anchor to arrive at final judgement.lThis suggests that you can bias a persons estimate if you pr

35、ovide the initial anchorAnchoring&Adjustment(Tversky and Kahneman,1974)lSome everyday examplesEstimating salary for a new employee:lBase it on past employees salary and adjust from there(regardless of changes to the job or new requirements,etc.)Car salesman attempting to anchor you to the“windscreen

36、 price”on carGood bargainers know this52行为决策理论行为决策理论 Daniel Kahneman Amos Tversky Nobel Prize 2019 (1937-2019)Anchoring&AdjustmentlSunk Cost Effectsl公司给了一张价值300元的明星演唱会门票，碰上大暴雨，去不去？l价值300元的票是自己买的，碰上大暴雨，去不去？54沉没成本沉没成本l新产品研发计划，据悉竞争对手已经开发出来，如果做下去，很大几率要损失500万。但有很小的几率可以获利2500万。做或不做？l新产品研发计划，已经投资500万，再丟50万

37、就可上市。据悉竞争对手已经开发出来，如果做下去，很大几率要损失500万。但有很小的几率可以获利2500万。做或不做？Another aspect of anchoringlConfirmation bias:Paying more attention to information that confirms ones own beliefs,regardless of the research(selective perception)(Hart&Bing)Our initial beliefs do not easily shift(are anchored),despite potenti

38、ally disconfirming evidencelExamples:Studies of the effects of smoking,caffeine,global warming,HRT,etc.lWhatever study supports our initial position we view as“more convincing”,“better designed”,“definitive”.Anchoring&Adjustment(Tversky and Kahneman,1974)lIn order to counteract this bias:Be aware of

39、 the problem of anchoring choose a different anchor and see the effect on the solution/decision le.g.avoid sticking too close to previous years numbers when making company forecastsProvide a range,not a single-point valueWork with multiple anchorslapproach key estimates from several starting points(

40、e.g.best-case/worst-case scenarios)Avoid considering only incremental decisionsGet good feedback lremain open to new information and constantly modify predictions with feedback from environment.过度自信过度自信Overconfidence许多心理学研究显示人们倾向于对他们的判断过分自信。尤其是专业人士通常夸大自己的知识和能力。结果表现为：当他们“希望”某种结果出现时（主观上）将这个结果出现的概率夸大为必

41、然事件；而当他们“不希望”某种结果出现时（主观上）将这个结果夸大为不可能事件。而且设定置信区间非常小（通俗讲就是夸大自己预测的准确性）。OverconfidencelTendency to be more certain of judgments regarding the likelihood of a future event than ones actual predictive accuracy warrants“过度自信过度自信”还在以下情况下尤其突出还在以下情况下尤其突出l所要完成的工作十分困难；l在预测能力有限的条件下进行预测；l执行缺乏快速和清晰的反馈的任务的时候；l是男性的时

42、候（男性似乎比女性更容易犯“过度自信”的毛病）。反过来对于一些较容易的任务或工作人们却显得有点自信不足。过度自信过度自信可表现为可表现为：“事后诸葛亮事后诸葛亮”和和“偏执偏差偏执偏差”l“事后诸葛亮”心理，指人们总会在事后调整自己的认识为自己在事前的判断和决策辩护。l“偏执偏差”指投资者执着于不成功的投资策略。这使这类投资者在市场上的投资表现相对较差。偏执偏差偏执偏差(Confirmatory Bias)Another aspect of anchoring指行为人不仅不依据新信息对他初始信念进行修正，反而将新信息错误理解为对他的原有信念的进一步证明。Paying more attentio

43、n to information that confirms ones own beliefs,regardless of the research(selective perception)(Hart&Bing)Our initial beliefs do not easily shift(are anchored),despite potentially disconfirming evidencelExamples:Studies of the effects of smoking,caffeine,global warming,HRT,etc.lWhatever study supports our initial position we view as“more convincing”,“better designed”,“definitive”.Confirmation biasHope you more creative and considerate!