Showing posts with label dynamic inconsistency. Show all posts
Showing posts with label dynamic inconsistency. Show all posts

Sunday, August 20, 2023

Ainslie (2021) on Willpower

George Ainslie, “Willpower With and Without Effort.” Behavioral and Brain Sciences 44, e30: 1–16, 2021, pdf here. [This "target" article attracted 26 commentaries, which can be found here. Ainslie's response to the commentaries is here.]

• The basic framework: a Smaller, Sooner (SS) option versus a Larger, Later (LL) option. 

• The SS option is tempting in the moment, even if the LL option is valued more highly at other points of time. 

• Why is SS tempting? Perhaps visceral factors take over, or hyperbolic discounting does its thing. “Preference for the [SS] option is often temporary…[p. 2].” 

• Two different mechanisms, suppression and resolve, are commonly associated with willpower. Habit is a third willpower-adjacent mechanism that can be distinguished from resolve (or from a lack of resolve). 

• Suppression involves avoiding (or blocking or ignoring) the re-evaluation of the two alternatives while waiting for the LL. (Cue the marshmallow test!) Suppression “is necessarily unstable [p. 1],” a “game of keep away [p. 5].” Suppression requires attention, and thus precludes other uses of mental resources that might themselves be rewarding. 

Resolve refers to sticking with the original valuations by cognitively changing the stakes. “Recursive self-prediction” seems to be a leading approach to resolve, and underlies personal rules. Resolve “is intent that is maintained by an enforcement mechanism [p. 5].” One resolve mechanism is to raise the stakes by viewing giving into temptation not as a one-time deviation, but as the start or continuation of a long series of lapses. (Suppression can be one device for building resolve.) 

• Hyperbolic discounting can be a basis for why people choose the LL alternatives when making category-wide choices, and why they try to bundle individual choices into those larger categories. 

Scale mismatch makes it hard to overcome current temptations – what would be the harm of eating this tempting dessert? (p.5) The harm lies in undermining the credibility of your weight-control plan. So, there is value in viewing your current choice as a test case. 

• There can be significant value in (legalistic?) distinctions to permit occasional deviations, so that you can give in to temptation to a degree without destroying the credibility of your long-term plan. (What happens in Vegas...)

• "Resolve becomes effortless to the extent that you are confident of maintaining it [p. 8]."

• Habit is a “routine simplification of action [p. 2]” which is not the same as resolve. With habit, the issue is moved out of the choice domain, behavior becomes arational. Ainslie distinguishes routine habits (like showering in the morning) from good habits ("preserved by resolve" and put at risk by unexcused lapses) and bad habits (repeated impulsive behaviors).

Thursday, September 1, 2022

Salas-Morellón, Palacios-Huerta, and Call (2021), “Dynamic Inconsistency in Great Apes"

Laura Salas-Morellón, Ignacio Palacios-Huerta, and Josep Call, “Dynamic Inconsistency in Great Apes,” July 2021. 

• People often display impatience when they are making decisions about rewards either right now or (larger rewards) with a slight delay. 

• The impatience is reduced if both the options are delayed, say, by an additional month; hence, there is a possibility for dynamic inconsistency, where people opt to be patient for choices concerning the distant future, but when those same choices become closer to the present, the less patient, immediate gratification choice becomes more attractive. 

• Do bonobos, gorillas, and orangutans – who share some 99% of their DNA with humans – display similar choice patterns? If they do, that suggests that human preferences are not due to human cultural factors, but are rather baked into us by our genetic make-up. 

• The "N" is quite small: 6 orangutans, 5 bonobos, and 4 gorillas. One of the gorillas was left out of the full experiment due to not meeting the pre-test criteria. 

• In the experiments, apes are offered the choice between an immediate reward (fruit) and a three-times-larger reward that is delayed by three minutes. 

• The same choices are again offered to apes, but this time, the “fast” reward arrives after three minutes, and the delayed reward arrives in nine minutes. 

• The apes prefer more to less, if the time delay is the same. 

• The apes prefer sooner to later, if the reward is the same. 

• The apes show more patience for the larger reward when both the options are delayed; that is, like humans, they seem to be subject to dynamic inconsistency in their intertemporal choices. 

• As the small sample-size suggests, the statistical significance of the results is quite limited.

Monday, June 22, 2020

Duckworth, Milkman, and Laibson (2019) on Willpower and Beyond

Angela L. Duckworth, Katherine L. Milkman, and David Laibson, “Beyond Willpower: Strategies for Reducing Failures of Self-Control.” Psychological Science in the Public Interest 19(3): 102-129, 2019.

• Higher self-control is associated with many good things -- but people struggle with self-control.

• Various models (such as dynamically inconsistent preferences) have been proposed to try to capture the workings (and failures) of self-control, and many strategies are deployed to try to bolster self-control. Exhortations to show more willpower, to just say no, are not that effective. That is, relying on willpower alone, as opposed to other strategies, is almost to give the game away.

• Strategies that try to make willpower more effective can usefully be categorized. In particular, some try to alter the situation (Situational strategies), and some try to target how the decision maker thinks about a given situation (Cognitive strategies). Further, some are undertaken by the decision maker herself (Self-Deployed strategies) and others are enacted by various outside actors, choice architects, including employers and regulators (Other-Deployed strategies). Self-Deployed strategies require that the decision maker understand, at least to some extent, her self-control shortcomings -- in the usual terminology, she must be somewhat sophisticated (not naive) about her intertemporal inconsistencies.

• Four categories of self-control strategies emerge within this two-dimensional framework, then: Self-Deployed Situational Interventions; Self-Deployed Cognitive Interventions; Other-Deployed Situational Interventions; and, Other-Deployed Cognitive Interventions. The authors list and discuss various strategies within each of these categories.

• Self-Deployed Situational Interventions attempt to manage the environment to reduce the need for self-control; such strategies include: deleting a game from your phone or employing other commitment devices (or commitment contracts) that reduce temptations or raise their effective prices; temptation bundling; removing temptations from view (which is one way to raise their effective price); and behavior therapy, such as removing "cues" from your environment when fighting an addiction.

• Self-Deployed Cognitive Interventions include: goal setting (which might be undertaken in public or in private); dividing the goal into bite-sized subgoals, and allowing for small wins along the way; explicit planning and implementation intentions (developing a detailed map of how a goal will be achieved); intensive self-monitoring (such as weighing yourself every day); psychological distancing from temptations or from interpersonal problems; mindfulness and cognitive therapy (generally provided in the form of Cognitive Behavioral Therapy).

• Other-Deployed Cognitive Interventions (which might not be recognized by the targets) include: descriptive social norms (like energy use by others in your neighborhood); social labeling (which might motivate you to live up to your identity, as a green consumer, say); age-processed renderings or other techniques to make one's own future self more relatable; and fresh-start framing, as with new year's resolutions.

• Other-Deployed Situational Interventions include: hard paternalism (e.g., social security, high sin taxes); microenvironments (healthy food placed at eye level); default settings or active choice mandates; requirements for choices to be made in advance; and planned interruptions (such as a mandated break on a slot machine, say).[Incidentally, as Loewenstein points out, hard paternalism does not bolster self-control but eliminates the need for self-control.]

Sunday, June 21, 2020

Fennell (2019), "Personalizing Precommitment"

Lee Anne Fennell, “Personalizing Precommitment.” University of Chicago Law Review 86(2): 433-458, March 2019.

• Achieving long-term goals such as losing weight or writing a book requires the cooperation of many temporal selves of the same individual -- and perhaps the indulgences of some Mr. Hydes will undermine Dr. Jekyll's best-laid schemes. Precommitment can help, and the law might have a role to play in making such precommitments more available.

 Fennell invokes the "scale mismatch" terminology of Drazen Prelec; scale mismatch is when the goal (such as losing weight) is achieved in aggregate terms but the steps (literally?) to achieve the goal are lots of small individual decisions.

• Rigid rules – exercise one hour every day – might work in overcoming these temporal internalities, but such rules might be excessive or so demanding that they are abandoned.

• Perhaps people can fashion their own, less rigid but more sustainable rules? Good choices of “partitions” and “menus” can aid the process. For instance, appropriate serving sizes and types of serving utensils and single-serve packaging: all of these nudges can contribute to achieving a weight-loss goal.

• Segmentation eases metering and monitoring. How much cake did I eat? It might be easier to know the answer when the cake is consumed in segmented units -- I had three cupcakes -- than when I just keep picking at some unsegmented blob o' cake.

• Writing a book might be made manageable by segmenting the task into chapters and sections. But…while smaller chunks are easier to complete, given scale mismatch, they also look less meaningful in terms of progress, and more capable of postponement.

• Instead of segmenting work time, what about segmenting time not spent working – like limiting breaks to ten minutes?

• Monetary issues often can be addressed with precommitments and partitions. Purchasing a home can be a sort of forced saving – but this commitment device can be undone by easily acquired home equity loans. Can programs be provided that allow people to opt into a "no home equity loans" condition? 

• People might try to earmark money for savings by having special accounts or even physical envelopes -- though the commitment can be undone if an emergency arises. In general, setting high savings targets with sub-partitions (so that prematurely opening one savings envelope does not mean that all the others are opened, too) looks like a pretty good strategy. Even precommitting some money to indulgences can aid the larger goal of saving money. Should bank savings accounts come with earmarked sub-accounts that are made salient in web-based representations, say?

 Online menus could be personalized, by removing some excessively tempting items at the consumer’s request. 

• Rigid rules such as “no dessert” prune the menu to two choices: comply or don’t comply: “the reason that they can be so effective – the extreme chunkiness of the choices they present – is also the reason why they often fail” 

• Rules change the effective payoffs: the good choice becomes more automatic, and the wrong choice bears a higher price. 

• Lapses can induce further failures. Ex ante, it often is best to believe that behavior is bundled, that a lapse today will mean a rapid downward spiral. (Fennell calls such notions "behavioral firewalls"; in this case, good behavior today prevents future bad behavior.) Ex post (after a lapse), however, it is best to believe that the lapse was anomalous, that it doesn’t fore-ordain future behavior. Now the firewall changes: future behavior must be sealed off from the lapse.

• As with money set aside for financial indulgences, limited, planned exceptions can be helpful – but perhaps not implementable, perhaps zero tolerance, rigid rules are needed. 

• Receiving an income tax refund can be a form of forced savings or a welcome source of wam – but private firms can offer products that undo the commitment element of tax refunds. The IRS, incidentally, provides a split-refund facility, to allow the funneling of part of a refund into savings.

Saturday, February 9, 2019

Sugden v. Sunstein on Nudging, Round 2: Sunstein's Turn

Cass R. Sunstein, “’Better Off, as Judged by Themselves’: A Comment on Evaluating Nudges.” International Review of Economics 65(1): 1-8, March 2018.

[Round 1 here; Round 3 here]

 In trying to improve wellbeing, individuals’ judgments of their own welfare are a central metric. This metric is complicated, however, if people have different judgments before and after a nudge, say. 

• Sugden argues that two potential interpretations of “as judged by themselves” (AJBT) are flawed, one by applying only to relatively rare self-control issues, and the second by allowing individual preferences to be sacrificed to the whims of nudgers. 

• Sugden's title asks if people really want to be nudged towards healthier living. The empirical answer is “yes.” 

• AJBT is not our method to rule out charges of paternalism, but rather, to limit the coercive element of paternalistic acts – like a GPS, we want to improve “navigability,” so people can better serve their own interests. Nudges are about means, not ends. 

 Reminders (such as text messages) serve people’s pre-nudge preferences -- likewise with information provision, as with calorie counts. Other nudges can change behaviors in a manner that the nudged individual endorses after-the-fact, but not before, such as a mechanism to dissuade texting while driving. 

• With self-control problems (akrasia), nudges might help to bolster Dr. Jekyll (planner) at Mr. Hyde’s (doer) expense. Sunstein asked folks online if they had a self-control problem: the majority said yes. And programs to ends addictions are quite popular. 

• Yes, preferences can be formed in the process of elicitation; for instance, people might stick with, and endorse, any of various default settings. Then nudgers are forming preferences, but AJBT limits what nudgers can do. 

• To summarize, some nudges serve ex ante preferences when they increase navigability; some help with (widespread!) self-control shortcomings; and some contribute to preference formation, but in a manner that still respects after-the-fact preferences.

Sunday, September 23, 2018

Monterosso and Ainslie (2007) on Recovery from Addiction

John Monterosso and George Ainslie, “The Behavioral Economics of Will in Recovery from Addiction.” Drug and Alcohol Dependence 90(Supplement 1): S100-S111, September 2007.

• Addicts have severe self-control issues with respect to the object of their ardor.

• The goal of this article is to suggest that behavioral economics ideas are fruitful not only in thinking about the process of building an addiction, but also in understanding recoveries from addiction.

• Dynamic inconsistency seems to be tied up in addiction: addicts often express (quite credibly) desires to quit or cut down, but do not follow through on those desires.

• But dynamic inconsistency might also suggest pathways out of addiction – and many treatment programs look to develop these pathways, which involve internal, not external, commitment devices (“private side-betting”).

• Drug use would not be a problem if the pain arose immediately, and the gratification arrived after a delay.

• “Hyperbolic discounting implies that the increase in valuation that occurs when moving a fixed unit of time closer to an expected outcome is proportionately greater the closer one is to that outcome. Think of the experience of waiting for an additional day for an important event that is a year off, versus for one that is imminent [p. 3].”

• Hyperbolic discounting sets one up for dynamic inconsistency of the immediate gratification variety; further, addicts tend to display higher discount rates than non-addicted people (though causality might go both ways). How is it that people with this sort of discounting ever recover, and become dynamically consistent with respect to their intentions to indulge in drugs, say?

• A hyperbolic discounter has a multitude of different (time-based) “interests” – it is Jekyll and Hyde and the rest of the London population, too.

• How does one “interest” protect itself against foreseeable future “interests”? One approach is to make the tempting act unavailable, or raise its cost – perhaps by announcing to your social circle that you are on a diet, for instance, or are having a Dryuary. Or maybe you can deflect your attention (subconsciously) from activities that lead to your problem activity, or develop a repugnance towards them.

• These approaches are not really about willpower; rather, they signal a sophisticated understanding of your own future lack of willpower. And yet many treatment programs harp on building willpower.

• Another method to bolster willpower is a form of mental accounting: you bundle current choices with a string of future choices. In this way, a choice to drink today isn’t just about drinking or not drinking today: a choice to drink means that you will make a similar choice in future days – and that prospect might be sufficiently harrowing to keep you from drinking today.

• Experiments show that humans and non-human animals do choose less impulsively when they know that the current choice will bind similar choices down the road.

• What if you knew that having a drink today would have no effect on your future behavior, that you were pre-determined to drink every future day? What if you were told that you were pre-determined to never drink again, whether or not you drink today? It looks like current abstention is bolstered by the notion that it can influence future choices! But people do abstain, so they must see a link between today’s choice and future choices.

• Bundling can arise when someone sees that “I’ll smoke today and quit tomorrow” will also apply tomorrow, ad infinitum. Then, the actual choices today are “I’ll smoke today and forever” or “I’ll stop today and not relapse.” The personal “rule” becomes “never smoke.”

• The situation is like an intrapersonal repeated prisoners’ dilemma: the only reason you choose to “cooperate” today is if you can thereby make it more likely that your future selves also will choose to cooperate.

• But recall: in iterated prisoners’ dilemmas, it is hard to restore cooperation after a single defection. Likewise, a single lapse from abstinence by a recovering addict can lead to a binge. This sort of behavior looks like it is better described by the “bundling” model or willpower, not a story of binding commitments.

• Why would an addict fall off the wagon?: “[T]o the extent that her abstinence is based on a bundling effect, the primary danger comes from factors that reduce her differential expectation of future abstinence as a function of current abstinence [p. 9].”

• This reduction of perceived danger can derive from overconfidence, underconfidence, or rationalization.

• Twelve-step programs emphasize that willpower is unreliable, yet their adherents seem to do better (than those in other treatment forms) in overcoming cravings.

• Twelve-step treatments seem to respond to the threats created by overconfidence, underconfidence, and rationalization. How? (1) powerlessness and its related credos; (2) the focus on abstinence and the permanence of addiction; and (3) the adoption of doable goals, such as “one day at a time,” while tracking the abstinence streak.

• “When a person structures her choices with personal rules she can be expected to express different preferences than she would if she were making a choice just on the basis of its own merits, and these preferences are apt to differ as well among categories of reward, according to their temporal distribution, emotional relevance, dangerousness, impulse control history, and doubtless many other factors [p. 12].” 

• There is a possibility for a deleterious positive feedback loop, where proximity to the temptation good (or a cue) increases the probability of consumption which increases appetite which leads to increased probability of consumption…

Monday, September 4, 2017

Professor Thaler’s American Economic Association Presidential Address

Richard H. Thaler, “Behavioral Economics: Past, Present, and Future.” American Economic Review 106(7): 1577–1600, 2016 (working paper pdf available here).

• Economics provides an approach to optimal decision making -- and that is well and good. But we should not let that model distract us from how people actually make decisions.

• When people make decisions, they make them as fallible Humans, not as textbook Econs. They remain fallible Humans irrespective of how often we are told that: (1) their decisions will look "as if" they are Econs; (2) their departures from the full Econ will be unsystematic; (3) when the stakes are high they will convert into Econs; (4) with time they will learn to be Econ; and, (5) the special magic of market settings will see to it that only Econs survive.

• Does the market "get prices right"? Consider the closed-end mutual fund with ticket symbol CUBA. Typically, CUBA is priced at about a 10-to-15 percent discount relative to its underlying assets. But after December 18, 2014, CUBA started to trade at a 70% premium over the value of its underlying securities, and premium pricing continued for about a year.

• Why? On December 18, 2014, President Obama announced that the US would normalize diplomatic relations with Cuba. The CUBA mutual fund has nothing to do with the country of Cuba.

• When Humans make decisions under uncertainty, the sort of preferences they display are not those of expected utility theory. Rather, many decisions seem to involve "prospect theory"-style preferences: (1) utility is based on changes in wealth from some reference point; (2) people are loss averse; and (3) people do not weight potential outcomes according to the objective probabilities.

• For intertemporal preferences, people often display a present bias, a taste for instantaneous gratification, and in many ways, do not exhibit exponential discounting.

• As with preferences, people also do not seem to hold fully rational beliefs. In particular, people display excessive optimism and excessive confidence in their beliefs.

• Actual choices are influenced by "supposedly irrelevant factors [p. 1595]," where the supposition of irrelevance is made within standard economic models. For instance, default settings tend to influence ultimate choices, even in high-stakes situations (such as retirement planning) where the defaults are less-than-optimal and easy to override.

• In the future, economic models will incorporate those behavioral features that best improve their predictive accuracy without imposing high costs in terms of complexity; "behavioral" will disappear as an adjective for a subset of economics, as all economics will be as behavioral as necessary.

Wednesday, April 5, 2017

Samek (2016) Nudges Schoolchildren to Drink Healthier Milk

Anya Samek, “Gifts and Goals: Behavioral Nudges to Improve Child Food Choice at School.” CESR-Schaeffer Working Paper Series, Paper No: 2016-007, January, 2016; available at SSRN.

• The author arranges for a field experiment to take place at eight public elementary schools in Chicago; the 1400 or so child subjects do not know that they are participating in an experiment. 

• The only lunch menu choice that is available to these schoolkids every day is whether to get the (low-fat) white milk, the (low-fat) chocolate milk, or do without milk altogether. On the first day of the experiment, students are nonchalantly observed when they make their milk choices. Chocolate milk is the big favorite: more than 85% of kids take the chocy, 11% take white, and 3.4% go milkless.

• In the second and final day of the experiment, a control and two treatment goups are implemented. In the control condition, teachers very briefly explain the relative merits of white milk (chocy milk has added sugar, and that is less healthy, you see) shortly before lunch. In the “Gift” condition, the explanation is followed up by a gift of a sticker to all students, no questions asked and nothing required in return; and in the third condition, “Goal,” students are asked to make an unenforceable goal, a written pledge, as it were, to choose the white milk (though they can pledge themselves to chocolate). 

• The control condition induces a huge increase in white milk purchasing, to over 47%. The Gift condition brings a slightly larger shift to white, with the Goal condition in between. The goal-setting “works” better for younger kids, but the sticker “works” about the same for everyone. 

• The unconditional gift tries (and seemingly succeeds) to connect the milk choice to reciprocity; one advantage of an unconditional gift is that no enforcement (of conditions) is needed. 

• The choices in the Goal group suggest a good deal of time inconsistency – lots of kids who pledge to get the white milk change their mind when the decision itself is at hand – even though the elapsed time between pledge and decision is only about 15 minutes. 

• The fact that the nudge and its recorded effects are of the one-day-only variety is a pretty severe restriction on drawing policy advice from the experiment. My main takeaway, as it were, concerns the large shift towards choosing white milk in the control condition: a very short piece of pro-white-milk propaganda delivered by a teacher alters lots of elementary student milk choices. Use this power wisely!

Monday, August 15, 2016

Bhattacharya, Garber, and Goldhaber-Fiebert (2015) on Exercise Nudges

Jay Bhattacharya, Alan M. Garber, and Jeremy D. Goldhaber-Fiebert, “Nudges in Exercise Commitment Contracts: A Randomized Trial.” NBER Working Paper 21406, July 2015.

• The authors implement a natural field experiment: people who browse their way to stickK.com looking to sign a contract that requires them to exercise regularly are randomized into one of three conditions. 

• The three conditions differ based upon the default length of the exercise commitment contract; the default (which is easy to override) can be 8 weeks, 12 weeks, or 20 weeks. More than 8,000 people take part in the experiment (unbeknownst to them, it seems), though some of the analysis relates to approximately 3,000 subjects for whom a longer period of data is available. 

• A nudge towards longer contract durations succeeds; that is, a 20-week default setting leads to longer duration actual contracts than do the shorter default terms. More than one-in-five contractors choose to put up monetary stakes – they lose money if they fail to exercise to the terms of the contract – that average $23 per week. 

• Not only does the 20-week nudge result in longer duration contracts, it induces more weeks of exercise – though the average weeks of successful exercise are less than half of the specified durations. 

• About 6% of the sample enters into a second commitment contract after the expiration of their earlier contract. The data suggest that people would be much more likely to sign a second exercise commitment contract if they were placed into a long (more than 18 weeks) initial commitment contract, as if the longer duration helps cement an exercise habit. 

• Following the reporting of their empirical results, the authors develop a parallel theoretical model. The model offers a four-period version of a quasi-hyperbolic utility function; the four periods allow for a pre-contract period and, later, the option of signing a second contract. 

• The subjects are assumed to be present biased and sophisticated about their bias – after all, the subjects are interested in committing to exercise. Exercise in the model is a habit-forming good, but one involving current costs along with future benefits. Without commitment, present-biased people will choose to exercise too little, from the point of view of their own long-run (non-present-biased) preferences. 

• Small changes in the depreciation of exercise “capital” (which underpins the habit-forming nature of exercise) lead to large changes in optimal exercise choices. In contrast, even sizable changes in the degree of present bias have little impact on optimal exercise. 

• The authors offer a definition of a nudge that incorporates asymmetric or libertarian paternalism: a nudge in a given period t cannot decrease the person’s period t utility by very much. (But a nudge surely will decrease that utility, that is, it cannot make the period t person better off.) And though nudges must be small in this sense, they nevertheless can have a large effect on exercise choices, in particular, by helping to promote an exercise habit. A large nudge, however, can lead to so much present exercise that in future periods, exercise is eliminated, as the subject finds it optimal to rest on his or her exercise laurels. 

• Are sophisticated but present-biased people better off with a nudge? By definition, here, the person in the nudged period is not better off. Future selves can be helped or harmed, however – the overall welfare effects of nudges for a heterogeneous population are ambiguous.

Sunday, July 3, 2016

Sadoff, Samek, and Sprenger (2015) on Food-Related Time Inconsistency

Sally Sadoff, Anya Samek, and Charles Sprenger, “Dynamic Inconsistency in Food Choice: Experimental Evidence from a Food Desert.” January, 2015 [pdf].

• The authors present the results of a natural field experiment: the subjects did not know at the time that they were participating in an experiment. 

• The subjects receive $10 in a special budget each week for two weeks; they can buy ten units of food each week, as each unit costs $1. There are 20 different food items available, half of which are healthy, and half of which are unhealthy. The selected food items are delivered to the subjects’ homes. 

• At the onset, before selection or delivery, the more than 200 subjects rate how much they like the 20 food items. Then they choose their items for the first week’s delivery. 

• At the time of delivery of the ten selected items, the subjects are given a surprise presentation of four additional goods, which can be exchanged on a one-for-one basis with any of the delivered items; so, participants have an opportunity to partly change their minds. The four additional items are foods they rated highly, two healthy, two unhealthy, and include at least one item of each type that was not in the pre-arranged bundle. 

• The idea is that any exchanges made at the time of delivery are evidence of time inconsistency; the researchers focus on exchanges that alter the healthy-unhealthy mix: 21% (46 of 218) of the subjects show such an inconsistency, and 44 of those 46 move to a less healthy mix. 

• In the second week, one day before delivery, subjects are asked if they would again like the extra four items brought for a potential exchange (with their new, pre-arranged bundle). One-third of the subjects say “no thanks,” that is, they choose to commit to not being offered a future opportunity to exchange. 

• People who are dynamically consistent in week 1 are more likely (than are the dynamically inconsistent) to say "no thanks" to the offer to have the extra items available. That is, those subjects who successfully fight temptation in week 1 are those who make most intensive use of the commitment device that eliminates temptation. Further, those who prefer not to have the option to change tend to choose relatively healthy bundles in the first instance. 

• The theoretical underpinning of Sadoff et al. (2015) derives from articles by Gul and Pesendorfer, and by Fudenberg and Levine. In these models, the mere existence of a tempting good, even if it is not chosen, in a sense alters a consumer’s reference point in such a way that the value of consuming other goods is somewhat compromised by the tempting option. People in this situation, and who understand it, will want to restrict their options, even though they are eliminating options that they know they will not choose in any event. 

• In the O’Donoghue and Rabin (2003) approach (as described here), alternatively, it is only sophisticated, present-biased consumers who know that they would succumb to temptation who find it worthwhile to restrict their future options. 

• The analysis suggests that encouraging people to make their food choices well in advance of consumption might help spur the consumption of relatively healthy foods. (Note that the grocery deliveries in the experiment generally are not consumed right away, either, and hence the additional items might not be all that tempting. Gains to precommitment might be even larger in the face of more intense temptation.) 

Saturday, June 11, 2016

O’Donoghue and Rabin (2015) on Present Bias

Ted O’Donoghue and Matthew Rabin, “Present Bias: Lessons Learned and To Be Learned.” American Economic Review 105(5): 273–279, 2015 [pdf].

• In extending the standard exponential discounting model to incorporate present bias, the β, δ functional form has proven to be “useful, tractable, and (importantly) disciplined [p. 273].” Further, the β, δ approach seems to correlate well with the psychological findings, in that most of the action in terms of changing discount rates over time concerns right now versus the future. [For more on the quasi-hyperbolic, β, δ approach, see this Behavioral Economics Outlines post.] 

• If β is less than 1, and hence the individual displays present bias, we still need to inquire as to whether the person comprehends that she is present biased. A person who fully understands her taste for instantaneous gratification is termed “sophisticated,” whereas someone who fails to understand her present bias – she repeatedly says, and believes, that she will quit smoking tomorrow – is said to be “naïve.” People who recognize that they are present biased but underestimate the extent of their bias are partially sophisticated or partially naïve. 

• Without uncertainty or liquidity constraints, choices among monetary streams should be made by maximizing present value at market interest rates: individual preferences and discount rates are irrelevant. In low-stakes experiments, people are unlikely to be liquidity constrained; therefore, those choices should not depend on discounting. For this reason, recent experiments exploring present bias try to use real effort flows, not monetary streams. 

• Pairs of decisions, such as those involving credit card borrowing along with those involving retirement savings, can inform the calibration of present bias. The idea is that credit card purchases are influenced by present bias, whereas retirement decisions reflect long-run (β=1) preferences. 

• Welfare assessments are possible despite the non-unitary (over time) actors that present bias reflects; long run (that is, β=1) preferences have much to recommend them as the welfare criterion [example here]. 

• Don’t rush to “explain” heterogeneous behavior by different degrees of present bias. Habit persistence or tastes for tobacco probably explain more variance in smoking than does different degrees of present bias, for instance.

Wednesday, July 8, 2015

Giné, Karlan, and Zinman (2010) on Committing to Quit Smoking

Xavier Giné, Dean Karlan, and Jonathan Zinman, “Put Your Money Where Your Butt Is: A Commitment Savings Account for Smoking Cessation.” American Economic Journal: Applied Economics 2(4): 213-235, January 2010.

• Likely heavy smokers were randomly chosen to be offered a “Committed Action to Reduce and End Smoking” (CARES) savings account. After six months, a urine test was given to indicate whether the saver had given up smoking. A failed test meant that the money in the account was forfeited. A second treatment involved giving smokers aversive cue cards as opposed to the opportunity to open a CARES account. 

• CARES accounts were accompanied by weekly visits from a bank employee to collect additional deposits. Participants were urged to save the money they otherwise would have spent on cigarettes. The deposit collection seemed to be important for getting people to take up CARES. 

• Only eleven percent (a total of 83) smokers offered CARES signed up. Smokers randomly offered CARES were a bit more likely to pass a second, surprise urine test after one year. (That is, most did not quit smoking, but quit rates were about 1/3 higher than for smokers not offered CARES.) The cue cards didn’t help induce smoking cessation, though almost everyone who was offered the cards took them. 

• About 2/3 of CARES clients lost their deposits by failing the urine test. They tended to have lower deposits, though, and may have cut down on their smoking (and spending on smoking), even if they didn’t quit. Is it ethical to offer relatively poor people a commitment savings account in the fore-knowledge that many of them will end up unable to collect their savings?

Ashraf, Karlan, and Yin (2006), on Commitment Savings Accounts

Nava Ashraf, Dean Karlan, and Wesley Yin, “Tying Odysseus to the Mast: Evidence From a Commitment Savings Product in the Philippines.” Quarterly Journal of Economics 121(2): 635-672, 2006.

• The authors conduct a natural field experiment to see if people will open a savings account that has no advantages except for barriers to withdrawal. The offered SEED accounts (“Save, Earn, Enjoy Deposits”) prevent depositors from accessing funds unless a target deposit amount or date is met. Most of the participants who opened accounts chose the date-based method. 

• Individuals were randomly chosen to be offered a SEED account, and about 28% of those who received the offer accepted it. Others were offered nothing or were given encouragement to save more. All the people involved were bank clients who already had a regular savings account. 

• All participants were given a survey aimed at identifying customers who had time inconsistent preferences. The survey indicated that 27.5% of respondents were hyperbolic, while a surprising 19.8% were reverse hyperbolic, more patient today than for future choices. Hyperbolic women (but not men) are more likely to take up the SEED offer. 

• The Intent to Treat (ITT) effect reveals the impact of being offered (not necessarily accepting) the SEED account. The ITT effect involved a significant increase in savings. (The encouragement-to-save option did not increase savings.) The Treatment on the Treated effect reveals the increase in savings for those who opened a SEED account relative to controls who would have opened one if offered; here, it is about four times higher than the ITT effect.

• Is it ethical to offer relatively poor people a type of savings account whereby it is more than conceivable that they will never be able to recover their funds because they did not reach their savings goal? After one year, only 6 of the 62 participants who opened an amount-based account achieved their goal and hence could access their funds (page 657).

Wednesday, July 1, 2015

O’Donoghue and Rabin Again, This Time, “Incentives and Self-Control” (2006)

Ted O’Donoghue and Matthew Rabin, “Incentives and Self Control.” In Richard Blundell, Whitney Newey, and Torsten Persson, eds., Advances in Economics and Econometrics: Volume 2: Theory and Applications (Ninth World Congress), Cambridge University Press, 2006, pp. 215-245 [pdf of pre-publication version here].

• Present biased people might gain through commitment, such as commitments to study or to exercise. Heterogeneity among individuals and uncertain future costs and opportunities, necessitate some flexibility in plans.

• The case against exponential discounting is similar to the case against expected utility theory: a slight bias for today versus next week, which seems perfectly reasonable, implies ridiculous decisions at longer time frames for exponential discounters. 

• Sophisticates can predict their own future self-control problems whereas naïfs are (blissfully?) unaware.

• People do not use the same discount rate for all decisions; they both plan for the long-term and give way to short-term indulgence. They hold both savings and credit card balances.

• You can alter incentives to influence present-biased folks without affecting exponential discounters. You can manipulate defaults, as with Save More Tomorrow, or mandate active choice.

• If the choice is to quit a habit now or later, many people will postpone their quitting, but if the choice is now or never, they will quit now. Naïfs don’t choose an addicted life course – they just choose one more day of addiction, again and again and again.

O’Donoghue and Rabin (2003) on Paternalism and Sin Taxes

Ted O’Donoghue and Matthew Rabin, “Studying Optimal Paternalism, Illustrated by a Model of Sin Taxes." American Economic Review 93(2): 186-191, May 2003.

• “Economists will and should be ignored if we continue to insist that it is axiomatic that constantly trading stocks or accumulating consumer debt or becoming a heroin addict must be optimal for the people doing these things merely because they have chosen to do it [page 186].” 

• In the quasi-hyperbolic utility function, Beta < 1 implies a time-inconsistent preference for immediate gratification. In the welfare (efficiency) analysis, this preference for immediate gratification is treated as an error. That is, society sides with the long-run Dr. Jekyll, not the impatient short-run Mr. Hyde. 

• In the model, potato chips have present benefits but future costs. The quasi-hyperbolic decision maker, or at least the Mr. Hyde component of that decision maker, undervalues those future costs. 

• What is the most efficient way for the government to raise (a given amount of) revenue through taxes on the two goods, carrots and potato chips? If there were no present bias, both goods should be taxed equally. But if some consumers display present bias, efficiency suggests taxing the tempting good, potato chips, at significantly higher rates. 

• High taxes on potato chips do not harm fully “rational” consumers much, but help present-biased people significantly by internalizing the “internality.” 

• Offering commitment options to sophisticated present-biased people could help them, with little or no cost to those who are not biased. (A sophisticated present-biased person is someone who understands that she is present biased, and hence might be willing to pre-commit in such a way as to restrain her future choices.)

• More generally, policy might want to take into account the possibility of less-than-rational behavior. Some policies that might be valuable include mandatory cooling-off periods, required information disclosure, and careful selection of default options.

Friday, June 19, 2015

Loewenstein and Thaler (1989) on Intertemporal Choice

George Loewenstein and Richard H. Thaler, “Intertemporal Choice.” Journal of Economic Perspectives 3(4): 181-193, Autumn, 1989.

• In choices over time involving money, people should discount at the interest rate – or at least so says standard optimization. But people are inconsistent in their revealed discount rate choices. 

• The discount rates that people implicitly employ seem to depend upon the magnitude of the sums involved, whether a gain or a loss is being evaluated, the time delay, and other factors. Discount rates fall with the length of time delay and the size of the reward, and discount rates are higher for gains than for losses. 

• Discount rates that vary with the time delay imply the possibility for dynamic inconsistency. If discount rates decline over time delays, for instance, then people will overconsume in the present, relative to their prior plans. 

• Workers seem to have a taste for increasing wage profiles over time, and economists have a hard time talking them out of it even when the standard economics arguments point in the other direction. Loss aversion, or fears of future self-control lapses, probably are part of the explanation. 

• Savoring and dread also alter time preferences in ways that do not conform neatly to the standard model.