Research
Publications
Motivating vaccination with financial incentives (Trends in Cognitive Sciences, 2023, Vol. 27(12), pp. 1099-1101; with Pol Campos-Mercade, Armando Meier and Devin Pope)
Governments and organizations often offer cash payments for vaccination. How effective are such payments? A literature review shows that incentives usually increase vaccination, especially for nonhesitant populations and when using guaranteed payments. Concerns about negative unintended consequences are unsupported. We also discuss open questions and avenues for future research.
Financial incentives for vaccination do not have negative unintended consequences (Nature, 2023, Vol. 613(7944), pp. 526-533; co-lead author; with Pol Campos-Mercade, Armando Meier, Stephan Meier, Devin Pope and Erik Wengström)
Financial incentives to encourage healthy and prosocial behaviours often trigger initial behavioural change, but a large academic literature warns against using them. Critics warn that financial incentives can crowd out prosocial motivations and reduce perceived safety and trust, thereby reducing healthy behaviours when no payments are offered and eroding morals more generally. Here we report findings from a large-scale, pre-registered study in Sweden that causally measures the unintended consequences of offering financial incentives for taking the first dose of a COVID-19 vaccine. We use a unique combination of random exposure to financial incentives, population-wide administrative vaccination records and rich survey data. We find no negative consequences of financial incentives; we can reject even small negative impacts of offering financial incentives on future vaccination uptake, morals, trust and perceived safety. In a complementary study, we find that informing US residents about the existence of state incentive programmes also has no negative consequences. Our findings inform not only the academic debate on financial incentives for behaviour change but also policy-makers who consider using financial incentives to change behaviour.
Competition and moral behavior: A meta-analysis of forty-five crowd-sourced experimental designs (PNAS, 2023, large-scale collaboration lead by C. Huber, A. Dreber, F. Holzmeister, J. Huber, M. Johannesson, M. Kirchler and U. Weitzel)
Monetary Incentives Increase COVID-19 Vaccinations (Science, 2021, Vol. 374(6569), pp. 879-882; co-lead author; with Pol Campos-Mercade, Armando Meier, Stephan Meier, Devin Pope and Erik Wengström)
The stalling of COVID-19 vaccination rates threatens public health. To increase vaccination rates, governments across the world are considering the use of monetary incentives. Here we present evidence about the effect of guaranteed payments on COVID-19 vaccination uptake. We ran a large preregistered randomized controlled trial (with 8286 participants) in Sweden and linked the data to population-wide administrative vaccination records. We found that modest monetary payments of 24 US dollars (200 Swedish kronor) increased vaccination rates by 4.2 percentage points (P = 0.005), from a baseline rate of 71.6%. By contrast, behavioral nudges increased stated intentions to become vaccinated but had only small and not statistically significant impacts on vaccination rates. The results highlight the potential of modest monetary incentives to raise vaccination rates.
Prosociality predicts health behaviors during the COVID-19 pandemic (Journal of Public Economics, 2021, Vol. 195, 104367; with Pol Campos-Mercade, Armando Meier and Erik Wengström)
Socially responsible behavior is crucial for slowing the spread of infectious diseases. However, economic and epidemiological models of disease transmission abstract from prosocial motivations as a driver of behaviors that impact the health of others. In an incentivized study, we show that a large majority of people are very reluctant to put others at risk for their personal benefit. Moreover, this experimental measure of prosociality predicts health behaviors during the COVID-19 pandemic, measured in a separate and ostensibly unrelated study with the same people. Prosocial individuals are more likely to follow physical distancing guidelines, stay home when sick, and buy face masks. We also find that prosociality measured two years before the pandemic predicts health behaviors during the pandemic. Our findings indicate that prosociality is a stable, long-term predictor of policy-relevant behaviors, suggesting that the impact of policies on a population may depend on the degree of prosociality.
The impact of stay-at-home policies on individual welfare (Scandinavian Journal of Economics, 2021, Vol. 124(2), pp. 340-362; with Ola Andersson, Pol Campos-Mercade, Fredrik Carlsson and Erik Wengström)
This paper reports the results of a choice experiment designed to assess the impact of stay-at-home policies on individual welfare. We estimate the willingness to accept compensation (WTA) for restricting non-working hours away from home in a general population sample in Sweden during the COVID-19 pandemic. The WTA for a one-month stay-at-home policy is about $480 per person, which amounts to 9.1 percent of Sweden's monthly per capita GDP. Stricter and longer lockdowns require disproportionately more compensation than more lenient ones, indicating that strict policies are cost-effective only if they are much more successful in slowing the spread of the disease. Moreover, older people have a much higher WTA of staying home than the rest of the population, which should be considered when discussing policies targeting the elderly.
On self-serving strategic beliefs (Games and Economic Behavior, 2020, Vol. 122, pp. 341-353; with Nadja R. Ging-Jehli and Roberto A. Weber)
We experimentally study whether individuals adopt negative beliefs about others' intentions to justify egoistic behavior. Our first study compares the beliefs held by players with such an incentive to the beliefs of neutral observers and finds no evidence that individuals engage in “strategic cynicism.” This contrasts with other recent evidence demonstrating that people hold less positive beliefs about others when doing so allows them to act more self-interestedly. We reconcile the discrepancy, using a simple model of belief manipulation and a novel experiment that replicates and extends the earlier findings. Across three datasets, we find no evidence of negatively biased beliefs in absolute terms. However, those with a greater incentive to view others' intentions cynically exhibit relatively less positive beliefs. Our contribution expands our understanding of the psychological forces underlying self-serving belief manipulation, by noting that strategic cynicism may compete with a tendency towards positivity in determining individuals' beliefs.
An Experimental Test of the Anscombe-Aumann Monotonicity Axiom (Management Science, 2019, Vol. 65(4), pp. 1667-1677; with Martin Schonger)
Most models of ambiguity aversion satisfy the Anscombe–Aumann monotonicity axiom. Monotonicity implies a weak form of separability of preferences across events that occur with unknown probability. We construct a test of weak separability by modifying the Allais paradox, adapting it to the Anscombe–Aumann framework. Three experimental studies are conducted. Study 1 finds frequent, systematic violations of weak separability in the lab. These findings replicate in study 2, where we employ a subject pool of online workers and use a natural rather than an artificial source of uncertainty. Investigating a potential explanation of the violations, study 3 suggests that the certainty effect plays a major role. Our findings casts doubt on the “folding back” procedure frequently assumed in the Anscombe-Aumann framework.
Working Papers
Sorting and wage premiums in immoral work (with Fanny Brun and Roberto A. Weber; R&R at The Review of Economics and Statistics)
We use surveys, laboratory experiments and administrative data to study how heterogeneity in the perceived immorality of work and in workers’ aversion to acting immorally impact labor market outcomes. Immoral work is associated with higher wages, both in administrative data and in causal evidence from a laboratory experiment. Using distinct individual measures, we show that those who find immoral behavior least aversive are more likely to be employed in immoral work in the laboratory and exhibit a relative preference for work in sectors perceived as immoral. Such sorting may impact society through the resulting workforce composition across distinct sectors.
Signaling ideology through consumption
Firms often discourage certain categories of individuals from buying their products, seemingly at odds with typical assumptions about profit maximization. This paper provides a potential rationale for such firm behavior: Consumers seek to signal that they have “desirable” ideological values to themselves and others by avoiding products popular among people with “undesirable” values. In laboratory experiments and surveys, I provide causal evidence that consumption can be diagnostic of consumers’ ideologies and that demand for a product is lower if its customer base consists of individuals whose ideological values are widely considered undesirable. These effects occur for both observable and unobservable consumption and for products that do not possess any inherent ideological or undesirable qualities.
On the relative deservingness of capital and labor (with Vanessa Valero and Roberto A. Weber)
The allocation of production rewards between capital and labor is a topic of long-standing interest to economists, with recent growing attention due to rising capital shares and inequality. We study, using pre-registered experiments with representative samples of the US and the Swiss populations, perceptions of fairness in the allocation of rewards to work and investment. Our design holds constant many factors that may influence individuals’ policy preferences over such allocations. In the experiment, two participants provide separate inputs to production, either in the form of monetary investment or work effort; a different participant allocates the production rewards between the investor and the worker. We find substantial heterogeneity in perceived deservingness, but also observe a tendency to allocate a greater share to labor than to capital. Our measure of the tendency to favor one input over the other predicts attitudes and policy-relevant voting behavior in support of policies that differentially reward capital and labor. Overall, our findings indicate that people perceive different input factors as differentially deserving and that such fairness views directly impact policy preferences.
Self-serving biases in beliefs about collective outcomes (with Shimon Kogan and Roberto A. Weber)
Beliefs about collective outcomes, such as economic growth or firm profitability, play an important role in many contexts. We study biases in the formation of such beliefs. Specifically, we explore whether over-optimism and self-serving biases in information processing—documented for beliefs about individual outcomes—affect beliefs about collective outcomes. We find that people indeed exhibit self-serving biases for collective outcomes, and that such biases are similar to biases for individual outcomes. In addition, we investigate whether collective self-delusion is mitigated by market institutions. If anything, biases in information processing are more pronounced in the presence of a market.
Work in progress
What Money Shouldn’t Buy: Aversion to Monetary Incentives for Health Behaviors (with Pol Campos-Mercade, Armando Meier, Roberto A. Weber)
Behavioral policy targeting: Evidence from payments for vaccinations (with Pol Campos-Mercade, Armando Meier, Stephan Meier, Devin Pope and Erik Wengström)
Economic factors and support for physician-assisted dying (with Nicola Lacetera and Roberto A. Weber)
Social Preferences and Education (with Sanna Bergvall, Pol Campos-Mercade, Eva Ranehill and Erik Wengström)
The Dynamics of Organizational Culture (with Roberto A. Weber and Nina Xue)
Weighting Competing Narratives (with Chiara Aina)