This resource will be continuously updated as new papers are discovered and published.
No evidence for nudging after adjusting for publication bias
“Thaler and Sunstein’s “nudge” (1) has spawned a revolution in behavioral science research. Despite its popularity, the “nudge approach” has been criticized for having a “limited evidence base” (e.g., ref. 2). Mertens et al. (3) seek to address that limitation with a timely and comprehensive metaanalysis. Mertens et al.’s headline finding is that “choice architecture [nudging] is an effective and widely applicable behavior change tool” (p. 8). We propose their finding of “moderate publication bias” (p. 1) is the real headline; when this publication bias is appropriately corrected for, no evidence for the effectiveness of nudges remains (Fig. 1).”
RCTs to Scale: Comprehensive Evidence from Two Nudge Units
“We compare these trials to a separate sample of nudge trials published in academic journals from two recent meta-analyses. In papers published in academic journals, the average impact of a nudge is very large – an 8.7 percentage point take-up increase over the control. In the Nudge Unit trials, the average impact is still sizable and highly statistically significant, but smaller at 1.4 percentage points. We show that a large share of the gap is accounted for by publication bias, exacerbated by low statistical power, in the sample of published papers…”
Acceptable losses: the debatable origins of loss aversion
“It is often claimed that negative events carry a larger weight than positive events. Loss aversion is the manifestation of this argument in monetary outcomes. In this review, we examine early studies of the utility function of gains and losses, and in particular the original evidence for loss aversion reported by Kahneman and Tversky (Econometrica 47:263-291, 1979). We suggest that loss aversion proponents have over-interpreted these findings. Specifically, the early studies of utility functions have shown that while very large losses are overweighted, smaller losses are often not. In addition, the findings of some of these studies have been systematically misrepresented to reflect loss aversion, though they did not find it. These findings shed light both on the inability of modern studies to reproduce loss aversion as well as a second literature arguing strongly for it.”
The Loss of Loss Aversion: Will It Loom Larger Than Its Gain?
“Loss aversion, the principle that losses loom larger than gains, is among the most widely accepted ideas in the social sciences. The first part of this article introduces and discusses the construct of loss aversion. The second part of this article reviews evidence in support of loss aversion. The upshot of this review is that current evidence does not support that losses, on balance, tend to be any more impactful than gains. The third part of this article aims to address the question of why acceptance of loss aversion as a general principle remains pervasive and persistent among social scientists, including consumer psychologists, despite evidence to the contrary. This analysis aims to connect the persistence of a belief in loss aversion to more general ideas about belief acceptance and persistence in science. The final part of the article discusses how a more contextualized perspective of the relative impact of losses versus gains can open new areas of inquiry that are squarely in the domain of consumer psychology.”
Loss aversion fails to replicate in the coronavirus pandemic: Evidence from an online experiment
“Loss aversion is a foundational bias and is a natural choice for interventions encouraging compliance during COVID-19. We compare the effectiveness of loss and gain messages and find no difference in the intention to comply with guidance or lockdown beliefs.”
Revise the Belief in Loss Aversion
“The applications from Prospect theory have been phenomenal and the theory is arguably one of the most influential ideas in the whole of social sciences (Camerer, 2005). There is no contention about Prospect Theory being a key insight that significantly influenced intellectual development in economics and psychology. Nevertheless, it is time to take a critical look (Gal and Rucker, 2018) in at least two folds: (i) what is loss aversion? and (ii) how confident are we about its empirical evidence?”
The entitlement effect in the ultimatum game – does it even exist?
“Since the seminal paper of Hoffman et al. (1994), an entitlement effect is believed to exist in the Ultimatum Game, in the sense that proposers who have earned their role (as opposed to having it randomly allocated) offer a smaller share of the pie to their matched responder. The entitlement effect is at the core of experimental Public Choice – not just because it concerns the topics of bargaining and negotiations, but also because it relates to the question about under which circumstances actors behave more rational. We conduct three experiments, two in the laboratory and one online, with more than 1,250 participants. Our original motivation was to study gender differences, but ultimately we could not replicate the entitlement effect in the Ultimatum Game in any of our three experiments. Potential reasons for why the replication attempts fail are discussed.”
Impatience and Savoring vs. Dread: Asymmetries in Anticipation Explain Consumer Time Preferences for Positive vs. Negative Events
“For positive experiences (e.g., when to eat a snack), consumers generally prefer to have them immediately, and for negative experiences (e.g., when to pay a bill), consumers often prefer to delay. Yet, across three studies (plus twelve supplemental studies) we find that anticipatory feelings push in the opposite direction, and do so differently for positive vs. negative events, leading to different time preferences: The desire for immediate positives is stronger than the desire to delay negatives. For negative events, anticipatory utility is strongly negative, reducing the desire to delay bad things (i.e., consumers want to “get it over with” to minimize the psychological discomfort), but for positive events, overall anticipatory utility is weakly positive, and therefore does little to reduce consumers’ desire to expedite good things. This anticipatory asymmetry happens because when consumers think about a future positive event, they both enjoy imagining it (savoring) while simultaneously disliking the feeling of waiting for it (impatience), but when consumers think about a negative event, they both dislike imagining it (dread) and dislike the feeling of waiting for it. We demonstrate the managerial implications of these findings in a pair of field studies using online advertisements for retirement planning.”
Evidence of Fraud in an Influential Field Experiment About Dishonesty
What we can learn from five naturalistic field experiments that failed to shift commuter behaviour
“Across five field experiments with employees of a large organization (n = 68,915), we examined whether standard behavioural interventions (‘nudges’) successfully reduced single-occupancy vehicle commutes. In Studies 1 and 2, we sent letters and emails with nudges designed to increase carpooling. These interventions failed to increase carpool sign-up or usage. In Studies 3a and 4, we examined the efficacy of other well-established behavioural interventions: non-cash incentives and personalized travel plans. Again, we found no positive effect of these interventions. Across studies, effect sizes ranged from Cohen’s d = −0.01 to d = 0.05. Equivalence testing, using study-specific smallest effect sizes of interest, revealed that the treatment effects observed in four out of five of our experiments were statistically equivalent to zero (P < 0.04). The failure of these well-powered experiments designed to nudge commuting behaviour highlights both the difficulty of changing commuter behaviour and the importance of publishing null results to build cumulative knowledge about how to encourage sustainable travel.”
Assessing Global Organ Donation Policies: Opt-In vs Opt-Out
“This paper argues that there is little difference between opt-in and opt-out organ donation systems for increasing donor numbers when used in isolation. Independently diverting to an opt-out system confers no obvious advantage and can harm efforts to bolster donations. Rather, it is essential to address barriers to organ donation on several levels along with a switch in system. Moreover, for many countries, it may be more beneficial to adequately capacitate the donation system already in place, rather than entertain a significant change with its attendant resource requirements. For decades, the international transplant community has been involved in vigorous debate as to the merits of moving from default opt-in systems to opt-out policies to grow organ donor numbers and better meet the ever-increasing demand for lifesaving transplants. Opt-out is certainly en vogue, with Wales, England and Nova Scotia recently switching over, Scotland due to become opt-out in March 2021 and Northern Ireland and Canada seriously considering a similar move. Thanks to several countries making the switch from opt-in to opt-out over the last 20–30 years, there are sets of robust longitudinal data that aid in analysing the efficacy of donation systems. However, these data are often contradictory and largely inconclusive, suggesting other factors may be in play. This paper reviews some emerging trends in opt-in versus opt-out organ donation policies and considers recent data that elucidates some of the main contentions across each. Ethical frameworks underpinning donation systems, such as informed consent, trust and transparency, are discussed in detail. Substantial time is also devoted to opt-in vs opt-out systems in developing countries, which tend to be excluded from many analyses, and where the challenges faced are magnified by socio-economic constraints. This constitutes a major gap in recently published literature, as developing countries often lag far behind their developed counterparts in donor and transplant numbers.”
Opt-out legislations: the mysterious viability of the false
“It is frequently assumed that opt-out legislations set down a more favorable scenario to organ donation than do opt-in legislations. However, there are no clear examples of countries with a real sustained increase in organ donation after modifying the law. Arshad et al. performed a comparison that shows no significant differences between countries with these 2 legal systems. Health care providers must focus on actual barriers to increasing organ donation rather than on presumed consent alone.”
Comparison of organ donation and transplantation rates between opt-out and opt-in systems
“Studies comparing opt-out and opt-in approaches to organ donation have generally suggested higher donation and transplantation rates in countries with an opt-out strategy. We compared organ donation and transplantation rates between countries with opt-out versus opt-in systems to investigate possible differences in the contemporary era. Data were analysed for 35 countries registered with the Organisation for Economic Co-operation and Development (17 countries classified as opt-out, 18 classified as opt-in) and obtained organ donation and transplantation rates for 2016 from the Global Observatory for Donation and Transplantation. Compared to opt-in countries, opt-out countries had fewer living donors per million population (4.8 versus 15.7, respectively) with no significant difference in deceased donors (20.3 versus 15.4, respectively). Overall, no significant difference was observed in rates of kidney (35.2 versus 42.3 respectively), non-renal (28.7 versus 20.9, respectively), or total solid organ transplantation (63.6 versus 61.7, respectively). In a multivariate linear regression model, an opt-out system was independently predictive of fewer living donors but was not associated with the number of deceased donors or with transplantation rates. Apart from the observed difference in the rates of living donation, our data demonstrate no significant difference in deceased donation or solid organ transplantation activity between opt-out versus opt-in countries. This suggests that other barriers to organ donation must be addressed, even in settings where consent for donation is presumed.”
The Lie Detector: Israeli TV investigation into Dan Ariely’s research (Hebrew)
“Professor Dan Ariely has become one of the most recognized researchers in Israel and the world in the field of behavioral economics. His research, books and lectures have made him a household name in the world of academia and beyond, mainly around the field of truth and lies. But the investigation of “The Source” places question marks on some of his works and studies – were they even carried out? And if they were carried out, did Ariely carry them out as he describes?”
A Systematic Scoping Review of the Choice Architecture Movement: Toward Understanding When and Why Nudges Work
“In this paper, we provide a domain-general scoping review of the nudge movement by reviewing 422 choice architecture interventions in 156 empirical studies. We report the distribution of the studies across countries, years, domains, subdomains of applicability, intervention types, and the moderators associated with each intervention category to review the current state of the nudge movement. Furthermore, we highlight certain characteristics of the studies and experimental and reporting practices that can hinder the accumulation of evidence in the field. Specifically, we found that 74% of the studies were mainly motivated to assess the effectiveness of the interventions in one specific setting, while only 24% of the studies focused on the exploration of moderators or underlying processes. We also observed that only 7% of the studies applied power analysis, 2% used guidelines aiming to improve the quality of reporting, no study in our database was preregistered, and the used intervention nomenclatures were non-exhaustive and often have overlapping categories. Building on our current observations and proposed solutions from other fields, we provide directly applicable recommendations for future research to support the evidence accumulation on why and when nudges work.”
