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什麽是行為經濟學？
行為經濟學建立在對人類行為的實證觀察的基礎上，這些觀察表明，人們並不總是做出新古典經濟學家認為的“理性”或“最佳”決策，即使他們擁有可用的信息和工具。
例如，為什麽人們經常避免或推遲投資 401ks 或鍛煉，即使他們知道做這些事情會給他們帶來好處？ 為什麽賭徒在輸贏後往往會冒更大的風險，即使賠率保持不變，無論“連勝”如何？
行為經濟學解釋
https://news.uchicago.edu/explainer/what-is-behavioral-economics#:~:text=Behavioral%20economics%20combines
作者：馬克斯·維廷斯基
行為科學和經濟學查爾斯·R·沃爾格林傑出服務教授理查德·塞勒 (Richard Thaler) 概述了工作中“推動”的一些例子。
視頻由芝加哥大學提供
行為經濟學結合了經濟學和心理學的元素，以了解人們在現實世界中的行為方式和原因。 它與新古典經濟學不同，新古典經濟學假設大多數人都有明確的偏好，並根據這些偏好做出明智的、利己的決策。
行為經濟學受到芝加哥大學學者、諾貝爾獎獲得者理查德·泰勒的領域定義工作的影響，研究人們“應該”做什麽和他們實際做什麽之間的差異以及這些行為的後果。
什麽是行為經濟學？
行為經濟學建立在對人類行為的實證觀察的基礎上，這些觀察表明，人們並不總是做出新古典經濟學家認為的“理性”或“最佳”決策，即使他們擁有可用的信息和工具。
例如，為什麽人們經常避免或推遲投資 401ks 或鍛煉，即使他們知道做這些事情會給他們帶來好處？ 為什麽賭徒在輸贏後往往會冒更大的風險，即使賠率保持不變，無論“連勝”如何？
通過提出這樣的問題並通過實驗確定答案，行為經濟學領域將人視為容易受到情感和衝動影響並受到環境和情況影響的人。
這種特征與傳統經濟模型形成鮮明對比，傳統經濟模型將人們視為純粹理性的行為者（具有完美的自我控製能力，永遠不會忘記自己的長期目標），或者視為偶爾犯下隨機錯誤的人，這些錯誤從長遠來看會抵消 。
行為經濟學研究中出現的一些原則可以幫助經濟學家更好地理解人類經濟行為。 根據這些原則，政府和企業製定了政策框架來鼓勵人們做出特定的選擇。
行為經濟學研究的起源是什麽？特沃斯基和卡尼曼是誰？
行為經濟學自 20 世紀 80 年代以來不斷發展，但它有著悠久的曆史：根據塞勒的說法，該領域的一些重要思想可以追溯到 18 世紀蘇格蘭經濟學家亞當·斯密。
斯密經常因“看不見的手”的概念而被人們銘記，如果每個人都做出自己利己的決定，那麽“看不見的手”就會引導整體經濟走向繁榮——這是古典和新古典經濟學的一個關鍵概念。 但他也認識到，人們往往對自己的能力過於自信，更害怕失敗而不是渴望勝利，更傾向於追求短期利益而不是長期利益。 這些思想（過度自信、損失厭惡和自我控製）是當今行為經濟學的基本概念。
最近，行為經濟學早期源於以色列心理學家阿莫斯·特沃斯基和丹尼爾·卡尼曼關於不確定性和風險的研究。 在 20 世紀 70 年代和 80 年代，特沃斯基和卡尼曼在人們做出判斷的方式中發現了一些一致的偏見，發現人們在評估特定結果的可能性時經常依賴容易回憶的信息，而不是實際數據，這一概念被稱為“ “可用性啟發式。” 例如，如果人們讀過有關鯊魚或熊襲擊的報道，他們可能會認為鯊魚或熊的襲擊是一種常見的死亡原因，但這些事件實際上非常罕見。
特沃斯基和卡尼曼還通過“前景理論”證明了框架和損失厭惡會影響人們做出的選擇。 例如，如果有機會保證贏取 250 美元，或者賭博有 25% 的機會贏得 1,000 美元，而 75% 的機會一無所獲，大多數人都會選擇必贏。 但如果有機會保證損失 750 美元，或者有 75% 的機會損失 1,000 美元，還有 25% 的機會什麽都不損失，大多數人會冒著損失 1,000 美元的風險，希望自己什麽也不會損失的可能性微乎其微。
這個經典的例子表明，如果與獲得 1,000 美元的盈利相比，避免 1,000 美元的損失，人們更願意承擔更大的統計風險，這與預期效用理論相矛盾。 前景理論以及特沃斯基和卡尼曼的其他工作繼續為當今行為經濟學研究的許多領域提供信息。
理查德·泰勒和芝加哥大學的行為經濟學家在該領域的發展中發揮了什麽作用？
20 世紀 80 年代，理查德·塞勒 (Richard Thaler) 開始以特沃斯基和卡尼曼的工作為基礎，並與他們進行了廣泛的合作。 他現在是布斯商學院行為科學和經濟學查爾斯·R·沃爾格林傑出服務教授，如今被認為是行為經濟學領域的創始人。
塞勒在識別指導個人經濟決策的因素方麵的研究為他贏得了 2017 年瑞典央行紀念阿爾弗雷德·諾貝爾經濟科學獎。他的想法部分源於他在研究生院所做的一係列觀察，這些觀察使他 相信人們的行為以可預測的方式偏離了傳統經濟模式。
例如，塞勒觀察到，他和一位朋友願意因暴風雪而放棄開車去觀看體育賽事，因為他們獲得了免費門票。 但如果他們自己買票，他們會更願意去，盡管票價無論如何都是一樣的，而且在暴風雪中開車的危險性也沒有改變。 這是“沉沒成本謬誤”的一個例子，即人們不太願意放棄自己親自投資的項目，即使這意味著更多的風險。
塞勒還因普及“助推”概念而聞名，這是一種引導人們做出更好決策的概念手段。 “助推”利用了人類心理學和行為經濟學中的許多其他概念，包括心理賬戶，即人們根據環境以不同方式對待金錢的想法。 例如，人們更願意開車穿過城鎮，購買 20 美元的商品可以節省 10 美元，而不是購買 1,000 美元的商品可以節省 10 美元，盡管所付出的努力和節省的金額是相同的。
塞勒和其他芝加哥大學經濟學家——包括萊昂納多·布爾斯廷（Leonardo Bursztyn）、喬什·迪安（Josh Dean）、尼古拉斯·埃普利（Nicholas Epley）、奧斯坦·古爾斯比（Austan Goolsbee）、亞曆克斯·伊馬斯（Alex Imas）、約翰·李斯特（John List）、蘇珊·梅爾（Susan Mayer）、森德希爾·穆萊納坦（Sendhil Mullainathan）、德文·波普（Devin Pope）、麗貝卡·迪宗·羅斯（Rebecca Dizon Ross）和希瑟·薩森斯（Heather Sarsons）——繼續進行實證研究，包括現場實驗 ，從多個角度探索行為經濟學。
行為經濟學中的“助推”是什麽？
在行為經濟學中，“助推”是操縱人們的選擇以引導他們做出具體決定的一種方式：例如，將水果放在視線高度或高中食堂收銀機附近就是“助推”的一個例子 讓學生選擇更健康的選擇。 助推的一個重要方麵是它們不是強製性的：禁止垃圾食品不是助推，也不是懲罰人們選擇不健康的選擇。
塞勒關於助推的想法在他於 2008 年與前芝加哥大學法律學者、現哈佛大學教授卡斯·桑斯坦 (Cass Sunstein) 合著的《助推：改善有關健康、財富和幸福的決策》一書中得到普及。 企業和政府，包括巴拉克·奧巴馬總統領導下的美國政府，已經將泰勒和桑斯坦關於推動政策的想法采納了。
例如，自動讓員工加入 401k 計劃，並要求他們選擇退出，而不是為他們提供選擇加入的機會，這是鼓勵更好、更一致的退休儲蓄的一個例子。 另一項計劃尋求使器官捐贈成為標準做法，要求注冊駕駛執照的人表明他們是否願意捐贈。
塞勒和桑斯坦用來描述圍繞助推而設計的情況的正式術語是“自由主義家長主義”——自由主義是因為它保留選擇，但家長主義是因為它鼓勵某些行為。 用塞勒的話說：“如果你想讓人們做某事，就讓它變得簡單。”
行為經濟學術語指南
可用性啟發式是指人們在評估特定結果的可能性時通常依賴於容易回憶的信息，而不是實際數據。 例如，如果人們讀過有關鯊魚或熊襲擊的報道，他們可能會認為鯊魚或熊的襲擊是一種常見的死亡原因，但這些事件實際上非常罕見。
有限理性是指人們的認知能力、信息和時間都是有限的，從經濟學家的角度來看，並不總是能做出“正確”的選擇，即使有信息可以指引他們采取特定的行動方針。
這可能是因為他們無法快速綜合新信息； 因為他們忽視了這一點，而是選擇“跟著自己的直覺走”； 或者因為他們沒有時間充分研究所有選項。 該術語由諾貝爾獎獲得者、芝加哥大學校友 Herbert A. Simon（AB'36、PhD'43）於 1955 年創造。
有限的自我利益是指人們常常願意為自己選擇不太理想的結果，如果這意味著他們可以支持他人。 慈善事業的捐贈是有限個人利益的一個例子，誌願服務也是如此。 雖然這些是常見的活動，
它們不受傳統經濟模型的影響，傳統經濟模型預測人們的行為主要是為了實現自己以及直係親屬和朋友的目標，而不是陌生人的目標。
有限意誌力體現了這樣一種觀點：即使了解了最佳選擇，人們通常仍然會優先選擇能帶來最大短期利益的事物，而不是實現長期目標的漸進進展。 例如，即使我們知道鍛煉可以幫助我們實現健身目標，我們也可能無限期推遲，說我們“明天開始”。
損失厭惡是指人們更厭惡損失而不是渴望獲得收益。 例如，丟失一張 100 美元的鈔票可能比找到一張 100 美元的鈔票更痛苦。
前景理論是指卡尼曼和特沃斯基（Kahneman and Tversky，1979）所做的一係列實證觀察，他們詢問人們如何應對某些涉及輸贏的假設情況，從而使他們能夠描述人類經濟行為的特征。 損失厭惡是前景理論的關鍵。
沉沒成本謬誤認為，人們會繼續投資一個虧損的項目，僅僅是因為他們已經投入了大量資金，即使這意味著冒著更多損失的風險。
心理賬戶是指人們根據情況對金錢有不同的看法。 例如，如果天然氣價格下降，他們可能會開始購買優質天然氣，導致他們最終花費相同的金額，而不是利用較低價格帶來的節省。
插畫：Ann Yun，芝加哥大學創意學院
Behavioral economics, explained
By Max Witynski
Behavioral economics combines elements of economics and psychology to understand how and why people behave the way they do in the real world. It differs from neoclassical economics, which assumes that most people have well-defined preferences and make well-informed, self-interested decisions based on those preferences.
Shaped by the field-defining work of University of Chicago scholar and Nobel laureate Richard Thaler, behavioral economics examines the differences between what people “should” do and what they actually do and the consequences of those actions.
hat is behavioral economics?
Behavioral economics is grounded in empirical observations of human behavior, which have demonstrated that people do not always make what neoclassical economists consider the “rational” or “optimal” decision, even if they have the information and the tools available to do so.
For example, why do people often avoid or delay investing in 401ks or exercising, even if they know that doing those things would benefit them? And why do gamblers often risk more after both winning and losing, even though the odds remain the same, regardless of “streaks”?
By asking questions like these and identifying answers through experiments, the field of behavioral economics considers people as human beings who are subject to emotion and impulsivity, and who are influenced by their environments and circumstances.
This characterization draws a contrast to traditional economic models that have treated people as purely rational actors—who have perfect self-control and never lose sight of their long-term goals—or as people who occasionally make random errors that cancel out in the long run.
Several principles have emerged from behavioral economics research that have helped economists better understand human economic behavior. From these principles, governments and businesses have developed policy frameworks to encourage people to make particular choices.
Behavioral economics has expanded since the 1980s, but it has a long history: According to Thaler, some important ideas in the field can be traced back to 18th-century Scottish economist Adam Smith.
Smith is often remembered for the concept of an “invisible hand” that guides an overall economy to prosperity if each individual makes their own self-interested decisions—a key concept in classical and neoclassical economics. But he also recognized that people are often overconfident in their own abilities, more afraid of losing than they are eager to win and more likely to pursue short-term than long-term benefits. These ideas (overconfidence, loss aversion and self-control) are foundational concepts in behavioral economics today.
More recently, behavioral economics has early roots in the work of Israeli psychologists Amos Tversky and Daniel Kahneman on uncertainty and risk. In the 1970s and ’80s, Tversky and Kahneman identified several consistent biases in the way people make judgments, finding that people often rely on easily recalled information, rather than actual data, when evaluating the likelihood of a particular outcome, a concept known as the “availability heuristic.” For example, people may think shark or bear attacks are a common cause of death if they’ve read about one such attack, but the incidents are actually very rare.
With “prospect theory,” Tversky and Kahneman also demonstrated that framing and loss aversion influence the choices people make. For example, if presented with an opportunity to win $250 guaranteed or gamble on a 25% chance of winning $1,000 and a 75% chance of winning nothing, most people will choose the sure win. But if presented with the chance to lose $750 guaranteed or a 75% chance to lose $1,000 and a 25% chance to lose nothing, most people will risk losing $1,000, hoping for the slim chance that they will lose nothing at all.
This classic example demonstrates that people are more willing to take a greater statistical risk if it means avoiding a $1,000 loss versus obtaining a $1,000 win, which contradicts expected utility theory. Prospect theory and other work by Tversky and Kahneman continues to inform many areas of behavioral economics research today.
What role have Richard Thaler and behavioral economists at the University of Chicago played in the development of the field?
In the 1980s, Richard Thaler began to build on the work of Tversky and Kahneman, with whom he collaborated extensively. Now the Charles R. Walgreen Distinguished Service Professor of Behavioral Science and Economics at the Booth School of Business, he is today considered a founder of the field of behavioral economics.
Thaler’s research in identifying the factors that guide individuals’ economic decision-making earned him the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel in 2017. His ideas stem in part from a series of observations he made in graduate school that led him to believe that people’s behavior deviated from traditional economic models in predictable ways.
For example, Thaler observed that he and a friend were willing to forgo a drive to a sporting event due to a snowstorm because they had been given free tickets. But had they purchased the tickets themselves, they would have been more inclined to go, even though the tickets would have been valued at the same price regardless, and the danger of driving in the snowstorm unchanged. This is an example of the “sunk cost fallacy”—the idea that people are less willing to give up on projects they have personally invested in, even if it means more risk.
Thaler is also known for popularizing the concept of the “nudge,” a conceptual device for leading people to make better decisions. A “nudge” takes advantage of human psychology and a number of other concepts in behavioral economics, including mental accounting—the idea that people treat money differently based on context. For example, people are more willing to drive across town to save $10 on a $20 purchase than $10 on a $1,000 purchase, even though the effort expended and the amount of money saved would be the same.
Thaler and other UChicago economists—including Leonardo Bursztyn, Josh Dean, Nicholas Epley, Austan Goolsbee, Alex Imas, John List, Susan Mayer, Sendhil Mullainathan, Devin Pope, Rebecca Dizon Ross and Heather Sarsons—continue to conduct empirical research, including field experiments, that explore behavioral economics from multiple angles.
What is a “nudge” in behavioral economics?
In behavioral economics, a “nudge” is a way to manipulate people’s choices to lead them to make specific decisions: For example, putting fruit at eye level or near the cash register at a high school cafeteria is an example of a “nudge” to get students to choose healthier options. An essential aspect of nudges is that they are not coercive: Banning junk food is not a nudge, nor is punishing people for choosing unhealthy options.
Thaler’s ideas about nudges were popularized in Nudge: Improving Decisions about Health, Wealth, and Happiness, his 2008 book with former UChicago legal scholar Cass Sunstein, now of Harvard University. Businesses and governments, including the U.S. government under President Barack Obama, have adapted Thaler and Sunstein’s ideas about nudges into policy.
The formal term Thaler and Sunstein use to describe a situation designed around nudges is “libertarian paternalism”—libertarian because it preserves choice, but paternalistic because it encourages certain behavior. In Thaler’s words: “If you want people to do something, make it easy.”
Guide to behavioral economics terms
The availability heuristic refers to the idea that people often rely on easily recalled information, rather than actual data, when evaluating the likelihood of a particular outcome. For example, people may think shark or bear attacks are a common cause of death if they’ve read about one such attack, but the incidents are actually very rare.
Bounded rationality refers to the fact that people have limited cognitive ability, information and time, and do not always make the “correct” choice from an economist’s point of view, even if information is available that would point them toward a particular course of action.
This might be because they cannot synthesize new information quickly; because they ignore it and instead choose to “go with their gut”; or because they don’t have the time to fully research all options. The term was coined in 1955 by Nobel laureate and UChicago alum Herbert A. Simon, AB’36, PhD’43.
Bounded self-interest is the idea that people are often willing to choose a less-optimal outcome for themselves if it means they can support others. Giving to charity is an example of bounded self-interest, as is volunteering. While these are common activities, they are not captured by traditional economic models, which predict that people act mostly to further their own goals and those of their immediate family and friends, rather than strangers.
Bounded willpower captures the idea that even given an understanding of the optimal choice, people will often still preferentially choose whatever brings the most short-term benefit over incremental progress toward a long-term goal. For example, even if we know that exercising may help us obtain our fitness goals, we may put it off indefinitely, saying we will “start tomorrow.”
Loss aversion is the idea that people are more averse to losses than they are eager to make gains. For example, losing a $100 bill might be more painful than finding a $100 bill would be positive.
Prospect theory refers to a series of empirical observations made by Kahneman and Tversky (1979) in which they asked people about how they would respond to certain hypothetical situations involving wins and losses, allowing them to characterize human economic behavior. Loss aversion is key to prospect theory.
The sunk-cost fallacy is the idea that people will continue to invest in a losing project simply because they are already heavily invested, even if it means risking more losses.
Mental accounting is the idea that people think about money differently depending on the circumstances. For example, if the price of gas goes down, they may begin to buy premium gas, leading them to ultimately spend the same amount, rather than taking advantage of the savings offered by the lower price.
