Richard H. Thaler won the 2017 Nobel Prize in Economic Science for “his contributions to behavioral economics.”

In most of his work, Thaler has challenged the standard economist’s model of rational human beings.  He showed some of the ways that people systematically depart from rationality and some of the decisions that resulted. He has used these insights to propose ways to help people save, and save more, for retirement. Thaler also advocates something called “libertarian paternalism.”

Economists generally assume that more choices are better than fewer choices. But if that were so, argues Thaler, people would be upset, not happy, when the host at a dinner party removes the pre-dinner bowl of cashews. Yet many of us are happy that it’s gone. Purposely taking away our choice to eat more cashews, he argues, makes up for our lack of self-control. This simple contradiction between the economists’ model of rationality and actual human behavior, plus many more that Thaler has observed, leads him to divide the population into “Econs” and “Humans.” Econs, according to Thaler, are people who are economically rational and fit the model completely. Humans are the vast majority of people.

Thaler (1980) noticed another anomaly in people’s thinking that is inconsistent with the idea that people are rational. He called it the “endowment effect.” People must be paid much more to give something up (their “endowment”) than they are willing to pay to acquire it. So, to take one of his examples from a survey, people, when asked how much they are willing to accept to take on an added mortality risk of one in one thousand, would give, as a typical response, the number $10,000. But a typical response by people, when asked how much they would pay to reduce an existing risk of death by one in one thousand, was $200.

One of Thaler’s most-cited articles is Werner F. M. De Bondt and Richard Thaler (1985). In that paper they compared the stocks of “losers” and “winners.” They defined losers as stocks that had recently dropped in value and winners as stocks that had recently increased in value, and their hypothesis was that people overreact to news, driving the prices of winners too high and the prices of losers too low. Consistent with that hypothesis, they found that the portfolio of losers outperformed the portfolio of winners.

One of the issues to which Thaler applied his thinking is that of saving for retirement. In his book Misbehaving, Thaler argues that if everyone were an Econ, it wouldn’t matter whether employers’ default option was not to sign up their employees for tax-advantaged retirement accounts and let them opt in or to sign them all up and let employees opt out. There are transactions costs associated with getting out of either default option, of course, but they are small relative to the stakes involved. For that reason, argued Thaler, either option should lead to about the same percentage of employees taking advantage of the program. Yet Brigitte G. Madrian and Dennis F. Shea found[1] that before a company they studied had tried automatic enrollment, only 49 percent of employees had joined the plan. When enrollment became the default, 84 percent of employees stayed enrolled. That is a large difference relative to what most economists would have expected.

Thaler and economist Shlomo Benartzi, arguing that people tend to be myopic and heavily discount the future, helped design a private pension plan to enable people to save more. Called Save More Tomorrow, it automatically increases the percent of their gross pay that people save in 401(k) plans every time they get a pay raise. That way, people can save more without ever having to cut their current consumption expenditures. Many “Econs” were presumably already doing that, but this plan helps Humans, as well. When a midsize manufacturing firm implemented their plan, participants, at the end of four annual raises, had almost quadrupled their saving rate.

In their book Nudge, Thaler, along with co-author Cass Sunstein, a law professor, used behavioral economics to argue for “nudging” people to make better decisions. In each person, they argued, are an impulsive Doer and a farsighted Planner. In the retirement saving example above, the Doer wants to spend now and the Planner wants to save for retirement. Which preferences should be taken account of in public policy?

As noted earlier, Thaler believes in “libertarian paternalism.” In Nudge, he and Sunstein lay out the concept. The basic idea is to have the government set paternalist rules as defaults but let people choose to opt out at low cost. One example is laws requiring motorcyclists to wear helmets. That is paternalism. How to make it “libertarian paternalist?” They favorably cite New York Times columnist John Tierney’s proposal that motorcyclists who don’t want to wear helmets be required to take an extra driving course and show proof of health insurance.

In a review of Nudge, Thomas Leonard writes:

The irony is that behavioral economics, having attacked Homo Economicus as an empirically false description of human choice, now proposes, in the name of paternalism, to enshrine the very same fellow as the image of what people should want to be. Or, more precisely, what paternalists want people to be. For the consequence of dividing the self has been to undermine the very idea of true preferences. If true preferences don’t exist, the libertarian paternalist cannot help people get what they truly want. He can only make like an old fashioned paternalist, and give people what they should want.[2]

In some areas, Thaler seems to have departed from the view that long-term considerations should guide economic policy. A standard view among economists is that after a flood or hurricane, a government should refrain from imposing price controls on crucial items such fresh water, food, or plywood. That way, goes the economic reasoning, suppliers in other parts of the country have an incentive to move goods to where they are needed most and buyers will be careful not to stock up as much immediately after the flood or hurricane. In 2012, when asked about a proposed anti-price-gouging law in Connecticut, Thaler answered succinctly, “Not needed. Big firms hold prices firm. ‘Entrepreneurs’ with trucks help meet supply. Are the latter covered? If so, [the proposed law is] bad.”[3] What he was getting at is that, to some extent, we get the best of both worlds. Companies like Wal-Mart, worried about their reputation with consumers, will refrain from price gouging but will stock up in advance; one-time entrepreneurs, not worried about their reputations, will supply high-priced items to people who want them badly. But in a Marketplace interview in September 2017,[4] Thaler said, “A time of crisis is a time for all of us to pitch in; it’s not a time for all of us to grab.” He seemed to have moved from the mainstream economists’ view to the popular view.

One relatively unexplored area in Thaler’s work is how government officials show the same irrationality that many of us show and the implications of that fact for government policy.

Thaler earned his Bachelor of Arts degree with a major in economics at Case Western Reserve University in 1965, his Masters degree in economics from the University of Rochester in 1970, and his Ph.D. in economics from the University of Rochester in 1974. He was a professor at the University of Rochester’s Graduate School of Management from 1974 to 1978 and a professor at Cornell University’s Johnson School of Management from 1978 to 1995. He has been a professor at the University of Chicago’s Booth School of Business since 1995.

About the Author

David R. Henderson is the editor of The Concise Encyclopedia of Economics. He is also an emeritus professor of economics with the Naval Postgraduate School and a research fellow with the Hoover Institution at Stanford University. He earned his Ph.D. in economics at UCLA.

Selected Works

1980. Toward a Positive Theory of Consumer Choice,” Journal of Economic Behavior and Organization 1, No. 1, pp. 39-60.

1985. (with Werner F.M. De Bondt.) “Does the Stock Market Overreact?,” Journal of Finance, Vol. 40, pp. 793-805.

1992. The Winner’s Curse: Paradoxes and Anomalies of Economic Life. Princeton University Press.

2003. (with Cass R. Sunstein.) “Libertarian Paternalism,” American Economic Review, Vol. 93, No. 2, pp. 175-179.

2004. (with Shlomo Benartzi.) “Save More TomorrowTM: Using Behavioral Economics to Increase Employee Saving,” Journal of Political Economy, Vol. 112, No. S1, pp. S164-87.

2008. (with Cass Sunstein.) Nudge: Improving Decisions About Health, Wealth, and Happiness, New Haven: Yale University Press.

2015. Misbehaving: The Making of Behavioral Economics, New York: W.W. Norton.


[1] Brigitte C. Madrian and Dennis F. Shea, “The Power of Suggestion: Inertia in 401(k) Participation and Savings Behavior,” Quarterly Journal of Economics, Vol. CXVI, Issue 4, November 2001, pp. 1149-1187. At:

[2] Thomas Leonard, “Review of Richard Thaler and Cass Sunstein, Nudge: Improving Decisions about Health, Wealth, and Happiness.” Constitutional Political Economy 19(4): 356-360.



Related Links

Richard Thaler on Libertarian Paternalism, an EconTalk podcast, November 6, 2006.

Ariel Rubinstein on Game Theory and Behavioral Economics, an EconTalk podcast, April 25, 2011.

Ed Glaeser on the Economics of Paternalism, an EconTalk podcast, September 18, 2006.

Erik Matson on Adam Smith, David Hume, and the New Paternalists, a Great Antidote podcast, May 10, 2024.

Alejandra Salinas, Behavioral Economics: Method, Norms, and Policy, at Econlib, February 2023.

Michael L. David, Price Gouging is Fine, but Humans Are Better, at Econlib, November 6, 2017.

Richard B. McKenzie, Predictably Irrational or Predictably Rational? at Econlib, January 4, 2010.