【正文】 knowledge of them.[65] ? Illusion of external agency – when people view selfgenerated preferences as instead being caused by insightful, effective and benevolent agents ? Illusion of transparency – people overestimate others39。t pete with one39。s attention suddenly seems to appear with improbable frequency shortly afterwards. (see also recency illusion).[29] Decisionmaking, belief and behavioral biases (4/8) ? Gambler39。 行為決策的應(yīng)用 ? 一、心里帳戶 (mental accounting) ? 二、交易偏見 (Exchange bias or exchange anisotropy) ? 三、沉沒成本誤區(qū) (sunk cost fallacy) ? 四、稟賦效應(yīng) (Endowment Effect) ? 五、過度自信 (Overconfidence) Decisionmaking, belief and behavioral biases (1/8) ? Ambiguity effect – the tendency to avoid options for which missing information makes the probability seem unknown.[8] ? Anchoring or focalism – the tendency to rely too heavily, or anchor, on a past reference or on one trait or piece of information when making decisions. ? Attentional bias – the tendency to pay attention to emotionally dominant stimuli in one39。 ? 由不確定到確定性的變化給人感覺的效力很大：比如，由 p= p=這 10%的變化給人感覺的效力很大。 ? 弗里德曼和薩維奇提供了一個(gè)既有凹形部分又有凸形部分的效用函數(shù)來解決保險(xiǎn)與彩票的困惑 （ 圖 B)。假定對各方案所產(chǎn)生后果的精確科學(xué)估算如下所示。 ? 如果根據(jù)期望效用理論，這兩個(gè)博彩的回報(bào)是相同的。 ? 博彩 B： 50%可能性贏得 2023元， 50%可能性什么也得不到。 ?博彩 D： 50%可能性損失 2023元， 50%可能性什么也不損失。 一、確定效果 (certainty effect) ? 在 A和 B中，問卷的結(jié)果顯示有 82%的受訪者選擇博彩B。 ? 白撿的 100元所帶來的快樂，難以抵消丟失 100元所帶來的痛苦。 π表示與概率 p相對應(yīng)的決策權(quán)重， v反映結(jié)果的主觀價(jià)值，分配給每一結(jié)果一個(gè)量 v(x)。 卡尼曼 特沃斯基 ????????niiinnxvpxvpxvpxvpxvEXV12211)()()()(...)()()()()]([)(???? 前景理論 (Prospect Theory, PT) 前景理論 (Prospect Theory, PT) ? EU理論：是一個(gè) 規(guī)范性范式 的風(fēng)險(xiǎn)決策模型。因此， EU理論對人的風(fēng)險(xiǎn)決策的描述性效度一直受到懷疑 。 33 67 EU準(zhǔn)則 ?EU準(zhǔn)則： 一個(gè)決策變量的期望效用，就是它在不同自然狀態(tài)下的 效用值 乘上相對應(yīng)的發(fā)生概率之和。 阿萊斯悖論 (Allais paradox) ? 實(shí)驗(yàn)結(jié)果 1：絕大多數(shù)人選擇 A而不是 B。L7 行為決策 ? 詹文杰（教授 /博導(dǎo)） ? Office: 華中科技大學(xué)管理學(xué)院 611室 ? Tel: 02787556472 ? Email: ? 0( ) 0() xx xxvx ??? ?? ? ?? ， ， 學(xué)習(xí)目標(biāo) ? 了解阿萊斯悖論 ? 了解期望效用 (EU)理論的不足 ? 掌握前景理論 (PT) ? 掌握常用的行為決策效應(yīng)及其應(yīng)用 7 行為決策 ? 阿萊斯悖論 ? EU理論的修正 ? 前景理論 (PT) ? 行為決策的應(yīng)用 阿萊斯悖論 (Allais paradox) ? 法國經(jīng)濟(jì)學(xué)家、諾貝爾經(jīng)濟(jì)學(xué)獎獲得者莫里斯 即 : (100) (100) + (0) + (120) ? 實(shí)驗(yàn)結(jié)果 2：絕大多數(shù)人選擇 D而非 C。 式中： ? EU(ai) : 行動 ai 的期望效用； ? U(Oij) : 行動 ai在自然狀態(tài) θj下的 效用 ； ? p(θj ) : 自然狀態(tài) θj發(fā)生的概率。 ? 例如， EU理論難以解釋阿萊斯悖論、 Ellsberg悖論等現(xiàn)象； ? 沒有考慮現(xiàn)實(shí)生活中個(gè)體效用的模糊性、主觀概率的模糊性； ? 不能解釋偏好的不一致性、非傳遞性、不可代換性、“偏好反轉(zhuǎn)現(xiàn)象”、觀察到的保險(xiǎn)和賭博行為； ? 現(xiàn)實(shí)生活中也有對 EU理論中理性選擇上的優(yōu)勢原則和無差異原則的違背； ? 實(shí)際生活中的決策者對效用函數(shù)的估計(jì)也違背 EU理論的效用函數(shù)。 ???????niiinnxupxupxupxupxuEXU12211)()(...)()()]([)(? PT理論：是一個(gè) 描述性范式 的風(fēng)險(xiǎn)決策模型。而結(jié)果的定義與參考點(diǎn)相對應(yīng)，在價(jià)值尺度中以 0為參考點(diǎn)。稱之為 “損失規(guī)避” 。根據(jù)期望效用理論有： U(A) U(B)。 二、反射效果 (reflection effect) ? 在 A和 B中，問卷的結(jié)果顯示有 80%的人選擇博彩 A。 ? 在第二個(gè)實(shí)驗(yàn)中 (C/D)，隱含的財(cái)富參考點(diǎn)是 2023（即，假設(shè)你剛剛贏了 2023元）。但是由于問題的敘述方式不同，個(gè)人的選擇是不同的，這就是框架效應(yīng)的結(jié)果。 ? 情景一：對第一組被試（ N=152）敘述下面情景： ? 如果采用 A方案， 200人將生還。 ? 馬柯維茨通過將效用函數(shù)的一個(gè)拐點(diǎn)放在 “ 通用財(cái)富 ” (customary wealth)的位置上修改了弗里德曼和薩維奇的函數(shù) （ 圖 C) 。 決策權(quán)函數(shù) π(p) 是一個(gè)非線性函數(shù) ? “確定性效應(yīng)”導(dǎo)致權(quán)重函數(shù)的非線性。s environment and to neglect relevant data, when making judgments of a correlation or association. ? Availability heuristic – the tendency to overestimate the likelihood of events with greater availability in memory, which can be influenced by how recent the memories are, or how unusual or emotionally charged they may be. ? Availability cascade – a selfreinforcing process in which a collective belief gains more and more plausibility through its increasing repetition in public discourse (or repeat something long enough and it will bee true). ? Backfire effect – when people react to disconfirming evidence by strengthening their beliefs.[9] ? Bandwagon effect – the tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behavior. ? Base rate fallacy or base rate neglect – the tendency to base judgments on specifics, ignoring general statistical information.[10] ? Belief bias – an effect where someone39。s fallacy – the tendency to think that future probabilities are altered by past events, when in reality they are unchanged. Results from an erroneous conceptualization of the law of large numbers. For example, I39。s own particular strengths.[53] ? Social desirability bias the tendency to overreport socially desirable characteristics or behaviours and underreport socially undesirable characteristics or behaviours.[54] Decisionmaking, belief and behavioral biases (8/8) ? Status quo bias – the tendency to like things to stay relatively the same (see also loss aversion, endowment effect, and system justification).[55][56] ? Stereotyping – expecting a member of a group to have certain characteristics without having actual information about that individual. ? Subadditivity effect – the tendency to estimate that the likelihood of an event is less than the sum of its (more than two) mutually exclusive ponents.[57] ? Subjective validation – perception that something is true if a subject39。 ability to know them, and they also overestimate their ability to know others. ? Illusory superiority – overestimating one39。 perceptions of them (see also physical attractiveness stereotype).[64] ? Illusion of asymmetric insight – people perceive their knowledge of their peers to surpass their peers39。t fit then you must acquit. ? Risk pensation / Peltzman effect – the tendency to take greater risks when perceived safety increases. ? Selective perception – the tendency for expectations to affect perception. ? Semmelweis reflex – the tendency to reject new evidence that contradicts a paradigm.[52] ? Selection bias the distortion of a statistical analysis, resulting from the method of collecting samples. If the selection bias is not taken into account then certain conclusions drawn