nep-exp New Economics Papers
on Experimental Economics
Issue of 2023‒12‒18
twenty-six papers chosen by

  1. Design-based Estimation Theory for Complex Experiments By Haoge Chang
  2. Do Individualists and Collectivists Cooperate Differently? By Aidin Hajikhameneh; Erik O. Kimbrough; Brock Stoddard
  3. Differences in How and Why Social Comparison and Real-Time Feedback Impact Resource Use: Evidence from a Field Experiment By Mark A. Andor; Lorenz Goette; Michael K. Price; Anna Schulze Tilling; Lukas Tomberg
  4. Complexity and Learning Effects in Voluntary Climate Action: Evidence from a Field Experiment By Flörchinger, Daniela; Frondel, Manuel; Jarke-Neuert, Johannes; Perino, Grischa
  5. Social Norms and Individual Climate Protection Activities: A Framed Field Experiment for Germany By Engler, Daniel; Ziegler, Andreas; Gutsche, Gunnar; Simixhiu, Amantia
  6. Coordination with Differential Time Preferences: Experimental Evidence By Marina Agranov; Jeongbin Kim; Leeat Yariv
  7. Early Child Care and Labor Supply of Lower-SES Mothers: A Randomized Controlled Trial By Hermes, Henning; Krauß, Marina; Lergetporer, Philipp; Peter, Frauke; Wiederhold, Simon
  8. Self-nudging is more ethical, but less efficient than social nudging By Diederich, Johannes; Goeschl, Timo; Waichman, Israel
  9. Central Bank Digital Currency and Privacy: A Randomized Survey Experiment By Syngjoo Choi; Bongseob Kim; Young-Sik Kim; Ohik Kwon
  10. Why do committees work? By Breitmoser, Yves; Valasek, Justin
  11. Free Riding, Democracy and Sacrifice in the Workplace: Evidence from a Real Effort Experiment By Kamei, Kenju; Tabero, Katy
  12. Augmented Reality Technology as a Tool for Promoting Pro-environmental Behavior and Attitudes By Giuseppe Attanasi; Barbara Buljat Raymond; Agnès Festré; Andrea Guido
  13. Do Water Audits Work? By Jesper Akesson; Robert W. Hahn; Rajat Kochhar; Robert D. Metcalfe
  14. An Experimental Nash Program: A Comparison of Non-Cooperative v.s. Cooperative Bargaining Experiments By Michela Chessa; Nobuyuki Hanaki; Aymeric Lardon; Takashi Yamada
  15. Equal before the (expressive power of) law? By Luise Görges; Tom Lane; Daniele Nosenzo; Silvia Sonderegger
  16. Equal before the (expressive power of) law? By Luise Goerges; Tom Lane; Daniele Nosenzo; Silvia Sonderegger
  17. A Mother’s Voice: Impacts of Spousal Communication Training on Child Health Investments By Martina Bjorkman Nyqvist; Seema Jayachandran; Celine Zipfel
  18. Social Gaze in Team Cooperation: A Multiparty Eye Tracking Study By Nieken, Petra; Reuscher, Tom Frank
  19. Cournot Meets Bayes-Nash: A Discontinuity in Behavior in Finitely Repeated Duopoly Games By Cédric Argenton; Radosveta Ivanova-Stenzel; Wieland Müller
  20. Who is in favor of affirmative action? Representative evidence from an experiment and a survey By Herzog, Sabrina; Schildberg-Hörisch, Hannah; Trieu, Chi; Willrodt, Jana
  21. Equal Price for Equal Place? Demand-Driven Racial Discrimination in the Housing Market By Anthony Lepinteur; Giorgia Menta; Sofie R. Waltl
  22. Losing on the Home Front? Battlefield Casualties, Media, and Public Support for Foreign Interventions By Fetzer, Thiemo; Souza, Pedco CL; Eynde, Oliver Vanden; Wright, Austin L.
  23. Human Capital Affects Religious Identity: Causal Evidence from Kenya By Alfonsi, Livia; Bauer, Michal; Chytilová, Julie; Miguel, Edward
  24. Humanization of Virtual Assistants and Delegation Choices By Yang, Nanyin; Palma, Marco; Drichoutis, Andreas C.
  25. Can a light-touch graduation model enhance livelihood outcomes? Evidence from Ethiopia By Leight, Jessica; Alderman, Harold; Gilligan, Daniel; Hidrobo, Melissa; Mulford, Michael
  26. Would Monetary Incentives to COVID-19 vaccination reduce motivation? By Eiji Yamamura; Yoshiro Tsutsui; Fumio Ohtake

  1. By: Haoge Chang
    Abstract: This paper considers the estimation of treatment effects in randomized experiments with complex experimental designs, including cases with interference between units. We develop a design-based estimation theory for arbitrary experimental designs. Our theory facilitates the analysis of many design-estimator pairs that researchers commonly employ in practice and provide procedures to consistently estimate asymptotic variance bounds. We propose new classes of estimators with favorable asymptotic properties from a design-based point of view. In addition, we propose a scalar measure of experimental complexity which can be linked to the design-based variance of the estimators. We demonstrate the performance of our estimators using simulated datasets based on an actual network experiment studying the effect of social networks on insurance adoptions.
    Date: 2023–11
  2. By: Aidin Hajikhameneh; Erik O. Kimbrough; Brock Stoddard
    Abstract: Research in social science has shown the importance of individualism and collectivism (I/C) in human behavior. Individualists tend to see people in isolation, while collectivists are more prone to see people as interconnected members of groups, and this has consequences for behavior, governance, and economic outcomes. We examine the role of I/C on cooperation experimentally in infinitely repeated prisoner’s dilemmas (IRPD) played with in- and outgroup members. We predict that collectivists will be more cooperative, forgiving and defect less with in-group members than out-group members. Individualists are predicted to make similar strategic decisions for in- and out-group members. In an effort to causally affect the I/C scores of our subjects, as well as to strengthen in- and out-group connections, subjects completed a group-identity task prior to the I/C instrument and IRPD in the Strong Identity treatment. In our Weak Identity treatment, subjects completed a task on their own and were simply told they were assigned to groups. During the experiment, across supergames, subjects were randomly matched with in- and out-group partners. Findings reveal that our treatment effects are largely null. The only significant effect on strategic behavior was that larger defection payoffs led to more defection and less cooperation by subjects in all treatments. Key Words: Individualism, collectivism, cooperation, repeated games, strategy, experiments
    JEL: C91 C92 C73
    Date: 2023
  3. By: Mark A. Andor; Lorenz Goette; Michael K. Price; Anna Schulze Tilling; Lukas Tomberg
    Abstract: We compare the behavior and welfare effects of two popular interventions for resource conservation. The first intervention is social comparison reports (SC), which primarily provide consumers with information motivating behavioral change. The second intervention is real-time feedback (RTF), which primarily provides consumers with information facilitating behavioral change. In a field experiment with around 1, 000 participants, we directly observe the interventions’ effects on participants’ behavior. Further, we elicit participants’ willingness to pay for receiving the interventions, both before and after having experienced them for one month. We find that SC leads to a reduction in water use per shower by 9.4%, RTF by 28.8%, and the combination (BOTH) by 35.0%. Our willingness to pay results show that all interventions are highly valued by participants and that willingness to pay for RTF and BOTH is significantly higher than for SC. Furthermore, we find that the valuation of the interventions do not change following one-month experience. Our results suggest that while both interventions improve welfare, providing consumers with information facilitating behavioral change achieves a higher impact and a slightly higher welfare increase than providing consumers with information motivating behavioral change.
    JEL: C93 D12 Q25 Q55
    Date: 2023–11
  4. By: Flörchinger, Daniela; Frondel, Manuel; Jarke-Neuert, Johannes; Perino, Grischa
    JEL: C93 D83 Q54
    Date: 2023
  5. By: Engler, Daniel; Ziegler, Andreas; Gutsche, Gunnar; Simixhiu, Amantia
    JEL: Q54 D64 D83 D91 C93
    Date: 2023
  6. By: Marina Agranov (California Institute of Technology and NBER); Jeongbin Kim (Florida State University); Leeat Yariv (Princeton University, CEPR, and NBER)
    Abstract: The experimental literature on repeated games has largely focused on settings where players discount the future identically. In applications, however, interactions often occur between players whose time preferences differ. We study experimentally the effects of discounting differentials in infinitely repeated coordination games. In our data, differential discount factors play two roles. First, they provide a coordination anchor: more impatient players get higher payoffs first. Introducing even small discounting differentials reduces coordination failures significantly. Second, with pronounced discounting differentials, intertemporal trades are prevalent: impatient players get higher payoffs for an initial phase and patient players get higher payoffs in perpetuity afterward.
    Keywords: Repeated Games, Discounting, Intertemporal Trade, Experiments
    JEL: C73 C92 D15 D25
    Date: 2023–09
  7. By: Hermes, Henning; Krauß, Marina; Lergetporer, Philipp; Peter, Frauke; Wiederhold, Simon
    JEL: D90 J13 J18 J22 C93
    Date: 2023
  8. By: Diederich, Johannes; Goeschl, Timo; Waichman, Israel
    Abstract: Manipulating choice architectures to achieve social ends ('social nudges') raises problems of ethicality. Giving individuals control over their default choice ('selfnudges') is a possible remedy, but the trade-offs with efficiency are poorly understood. We examine under four different information structures how subjects set own defaults in social dilemmas and whether outcomes differ between the self-nudge and two exogenous defaults, a social (full cooperation) and a selfish (perfect free-riding) nudge. Subjects recruited from the general population (n = 1, 080) play a ten-round, ten-day voluntary contribution mechanism online, with defaults triggered by the absence of an active contribution on the day. We find that individuals' own choice of defaults structurally differs from full cooperation, empirically affirming the ethicality problem of social nudges. Allowing for self-nudges instead of social nudges reduces efficiency at the group level, however. When individual control over nudges is non-negotiable, self-nudges need to be made public to minimize the ethicality-efficiency trade-off.
    Keywords: Choice architecture, defaults, public goods, self-nudge, online experiment
    JEL: H41 C92 D91
    Date: 2023
  9. By: Syngjoo Choi; Bongseob Kim; Young-Sik Kim; Ohik Kwon
    Abstract: Privacy protection is among the key features to consider in the design of central bank digital currency (CBDC). Using a nationally representative sample of over 3, 500 participants, we conduct a randomized online survey experiment to examine how the willingness to use CBDC as a means of payment varies with the degree of privacy protection and information provision on the privacy benefits of using CBDC. We find that both factors significantly increase participants' willingness to use CBDC by up to 60% when purchasing privacy-sensitive products. Our findings provide useful insights regarding the design and the public's adoption of CBDC.
    Keywords: central bank digital currency (CBDC), privacy, randomized online survey experiment
    JEL: E40 E50 C90
    Date: 2023–11
  10. By: Breitmoser, Yves (Universität Bielefeld); Valasek, Justin (Dept. of Economics, Norwegian School of Economics and Business Administration)
    Abstract: We report on the results of an experiment designed to disentangle behavioral biases in information aggregation of committees. Subjects get private signals about the state of world, send binary messages, and finally vote under either majority or unanimity rules. Committee decisions are significantly more efficient than predicted by Bayesian equilibrium even with lying aversion. Messages are truthful, subjects correctly anticipate the truthfulness (contradicting limited depth of reasoning), but strikingly overestimate their pivotality when voting (contradicting plain lying aversion). That is, committees are efficient because members message truthfully and vote non-strategically. We show that all facets of behavior are predicted by overreaction, subjects overshooting in Bayesian updating, which implies that subjects exaggerate the importance of truthful messages and sincere voting. A simple one-parameteric generalization of quantal response equilibrium capturing overreaction covers 87 percent of observed noise.
    Keywords: committees; incomplete information; cheap talk; information aggregation; laboratory experiment; Bayesian updating; lying aversion; limited depth of reasoning
    JEL: C90 D71 D72
    Date: 2023–11–21
  11. By: Kamei, Kenju; Tabero, Katy
    Abstract: Teams are increasingly popular decision-making and work units in firms. This paper uses a novel real effort experiment to show that (a) some teams in the workplace reduce their members’ private benefits to achieve a group optimum in a social dilemma and (b) such endogenous choices by themselves enhance their work productivity (per work time production) – a phenomenon called the “dividend of democracy.” In the experiment, worker subjects are randomly assigned to a team of three, and they then jointly solve a collaborative real effort task under a revenue-sharing rule in their group with two other teams, while each individual worker can privately and independently shirk by playing a Tetris game. Strikingly, teams exhibit significantly higher productivity (per-work-time production) when they can decide whether to reduce the return from shirking by voting than when the policy implementation is randomly decided from above, irrespective of the policy implementation outcome. This means that democratic culture directly affects behavior. On the other hand, the workers under democracy also increase their shirking, presumably due to enhanced fatigue owing to the stronger productivity. Despite this, democracy does not decrease overall production thanks to the enhanced work productivity.
    Keywords: workplace democracy, moral hazard, experiment, free riding, teamwork
    JEL: C92 D02 D72 H42
    Date: 2023–05–01
  12. By: Giuseppe Attanasi (Sapienza University of Rome, Italy; BETA, University of Strasbourg, France; Université Côte d'Azur, CNRS, GREDEG, France); Barbara Buljat Raymond (Université Côte d'Azur, France; GREDEG CNRS); Agnès Festré (Université Côte d'Azur, France; GREDEG CNRS); Andrea Guido (Université Bourgogne Franche-Comté; Burgundy School of Business)
    Abstract: We test whether augmented reality (AR) can serve as a fundraising tool by providing a more immersive way of communicating about environmental issues. In two incentivized studies, we exposed people to AR visualizations illustrating the consequences of plastic pollution, and measure the effect on participant' psychological distance, concern, intention to act and real proenvironmental behavior (donation to pro-environmental organizations). Results show evidence of heterogeneous effects depending on participants’ self-reported pro-environmental attitudes and personal characteristics: following the intervention, individuals with low environmental engagement were likely to reduce their psychological distance, while the opposite happened for individuals engaged in sustainable practices. However, despite AR visualizations reduced the psychological distance of a subset of individuals, our experimental intervention did not increase donation levels. Taken together, our results raise concerns about the use of AR technologies in fundraising and highlight the need for personalised interventions that take into account the heterogeneity of target groups.
    Keywords: Augmented Reality (AR), experiment, decision making, environmental fundraising, psychological distance, pro-environmental behavior, pro-environmental attitudes
    Date: 2023–11
  13. By: Jesper Akesson; Robert W. Hahn; Rajat Kochhar; Robert D. Metcalfe
    Abstract: Water suppliers are showing greater interest in using different mechanisms to promote conservation. One such mechanism is conducting home water audits, which involves assessing water use and providing tailored suggestions for conserving water for residential customers. Yet, very little is known about the economic impacts of these water audits. This paper helps fill this gap by implementing a natural field experiment in the United Kingdom. The experiment involves randomly allocating 45, 000 water customers to a control group or to treatment groups that receive different behavioral encouragements to take-up an online water audit. Our analysis yields three main findings. First, encouraging subjects to participate in an audit with financial incentives reduces household consumption by about 17 percent over two months. Furthermore, we find that the size of the financial incentive used to encourage conservation matters for take-up, but not conservation. Second, notwithstanding these improvements in water conservation, the per capita net benefits of the intervention are close to zero under a wide range of assumptions. We also implement a marginal value of public funds approach that considers benefits and costs and we reach a similar conclusion. Third, we find that targeting of high users could double the effectiveness of the financial incentive interventions.
    JEL: H0 Q25
    Date: 2023–11
  14. By: Michela Chessa; Nobuyuki Hanaki; Aymeric Lardon; Takashi Yamada
    Abstract: This paper aims to contribute to the literature on Nash program by experimentally comparing the results of “structured” (non-cooperative) demand-based and offer-based mechanisms that implement the Shapley value as an ex-ante equilibrium outcome with the results of corresponding “semi-structured” (cooperative) bargaining procedures. A significantly higher frequency of the grand coalition formation, the higher efficiency, and the allocation belonging to the bargaining set is observed in the latter than in the former regardless of whether it is demand-based or an offer-based. While significant differences in the resulting allocations are observed between the two non-cooperative mechanisms, little difference is observed between the two cooperative procedures.
    Date: 2023–11
  15. By: Luise Görges (Leuphana Universität Lüneburg, Institut für Volkswirtschaftslehre); Tom Lane (Newcastle University Business School); Daniele Nosenzo (Department of Economics and Busi-ness Economics, Aarhus University); Silvia Sonderegger (School of Economics and Centre for Decision Research and Experimental Economics (CeDEx), University of Nottingham)
    Abstract: Building on findings showing that laws exert a causal effect on social norms, this paper investigates whether this “expressive power of law” differs by gen-der or race. We develop a model to show that such differences are theo-retically plausible. We then use an incentivized vignette experiment to test whether these differences are empirically relevant. Results from an online sample of around 4000 subjects confirm that laws causally influence social norms. However, we find little evidence of a differential effect across gender or race, suggesting that gender and race biases in the legal system are driven by other mechanisms than differences in the expressive power of law.
    Keywords: Social Norms; Law; Expressive Function of Law; Gender Gap; Racial Bias
    JEL: C91 C92 D9 K1 K42
    Date: 2023–11
  16. By: Luise Goerges (Leuphana University Lüneburg); Tom Lane (Newcastle University Business School); Daniele Nosenzo (Department of Economics and Business Economics, Aarhus University); Silvia Sonderegger (School of Economics and Centre for Decision Research and Experimental Economics, University of Nottingham)
    Abstract: Building on findings showing that laws exert a causal effect on social norms, this paper investigates whether this “expressive power of law†differs by gender or race. We develop a model to show that such differences are theoretically plausible. We then use an incentivized vignette experiment to test whether these differences are empirically relevant. Results from an online sample of around 4000 subjects confirm that laws causally influence social norms. However, we find little evidence of a differential effect across gender or race, suggesting that gender and race biases in the legal system are driven by other mechanisms than differences in the expressive power of law.
    Keywords: Social Norms, Law, Expressive Function of Law, Gender Gap, Racial Bias
    JEL: C91 C92 D9 K1 K42
    Date: 2023–11–29
  17. By: Martina Bjorkman Nyqvist (Stockholm School of Economics); Seema Jayachandran (Princeton University); Celine Zipfel (Stockholm School of Economics)
    Abstract: Building on prior evidence that mothers often have a stronger preference for spending on children than fathers do, we use a randomized experiment to evaluate the impacts of a communication training program for mothers on child health in Uganda. The hypothesis is that the training will enable women to better convey their knowledge and preferences to their husbands and, thereby, boost investments in children’s health. We find that the program increases spousal discussion about the family’s health, nutrition, and finances. It also increases women’s and children’s intake of animal-sourced foods as well as household spending on these foods. However, this did not impact households’ adoption of health-promoting behaviors or most child anthropometric measures in the short run.
    Keywords: Spousal Communication, Children's Health, Uganda
    JEL: D10 I12 O12
    Date: 2023–08
  18. By: Nieken, Petra; Reuscher, Tom Frank
    JEL: C71 C91 C92 D01 D83
    Date: 2023
  19. By: Cédric Argenton (CentER & TILEC, Tilburg University); Radosveta Ivanova-Stenzel (TU Berlin); Wieland Müller (VCEE, University of Vienna, CentER & TILEC, Tilburg University)
    Abstract: We conduct a series of Cournot duopoly market experiments with a high number of repetitions and fixed matching. Our treatments include markets with (a) complete cost symmetry and complete information, (b) slight cost asymmetry and complete information, and (c) varying cost asymmetries and incomplete information. For the case of complete cost symmetry and complete information, our data confirm the well-known result that duopoly players achieve, on average, partial collusion. However, as soon as any level of cost asymmetry or incomplete information is introduced, observed average individual quantities are remarkably close to the static Bayes-Nash equilibrium predictions.
    Keywords: Cournot; Bayesian game; Bayes-Nash equilibrium; repeated games; collusion; cooperation; experimental economics;
    JEL: D43 L13 C72 C92
    Date: 2023–11–21
  20. By: Herzog, Sabrina; Schildberg-Hörisch, Hannah; Trieu, Chi; Willrodt, Jana
    Abstract: Although affirmative action remains controversial, little is known about who supports or opposes it and why. This paper investigates preferences for affirmative action by combining causal evidence from an experiment on the role of self-serving motives and in-group favoritism with survey data on three different affirmative action policies. Our results rely on a population-representative sample from the US. We find that support for affirmative action is based both on self-serving motives and principled grounds (e.g., related to an individual's altruism, fairness perceptions, concerns for efficiency, and political views). By contrast, in-group favoritism and socio-demographic characteristics play a much smaller role.
    Keywords: support for affirmative action, self-serving motives, in-group fa-voritism, altruism, efficiency, fairness, discrimination
    JEL: C99 D01 D63 J78
    Date: 2023
  21. By: Anthony Lepinteur; Giorgia Menta; Sofie R. Waltl
    Abstract: Participants to an online study in Luxembourg are presented with fictitious real-estate advertisements and tasked to make an offer for each of them. A random subset is also shown sellers’ names that are strongly framed to signal their origins. Our randomised procedure allows us to conclude that, keeping everything else constant, a seller with a sub-Saharan African surname is systematically offered lower prices. Our most conservative estimates suggest that the average racial appraisal penalty is equal to roughly EUR 20, 000. This figure is highly heterogeneous and can amount up to around EUR 58, 000. Last, we provide evidence suggesting that this appraisal bias may very well pass through onto the final sales price and that it may be due to statistical discrimination.
    Keywords: Racial Discrimination; Housing; Randomised Online Experiment
    JEL: J15 R21 R31
    Date: 2023–11
  22. By: Fetzer, Thiemo (Department of Economics, University of Warwick and University of Bonn); Souza, Pedco CL (Department of Economics, Queen Mary University of London); Eynde, Oliver Vanden (Paris School of Economics and CNRS.); Wright, Austin L. (Harris School of Public Policy, University of Chicago)
    Abstract: How domestic constituents respond to signals of weakness in foreign wars remains an important question in international relations. In this paper, we study the impact of battlefield casualties and media coverage on public demand for war termination. To identify the effect of troop fatalities, we leverage the otherwise exogenous timing of survey collection across 26, 776 respondents from nine members of the International Security Assistance Force (ISAF) in Afghanistan. Quasi-experimental evidence demonstrates that battlefield casualties increase coverage of the Afghan conflict and public demand for withdrawal, with heterogeneous effects consistent with an original theoretical argument. Evidence from a survey experiment replicates the main results. To shed light on the media mechanism, we leverage a news pressure design and find that major sporting matches occurring around the time of battlefield casualties drive down subsequent coverage, and significantly weaken the effect of casualties on support for war termination. These results highlight the crucial role that media play in shaping public support for foreign military interventions
    Keywords: international security ; public opinion ; political economy ; Afghanistan ; NATO
    Date: 2023
  23. By: Alfonsi, Livia (UC Berkeley); Bauer, Michal (Charles University, Prague); Chytilová, Julie (Charles University, Prague); Miguel, Edward (University of California, Berkeley)
    Abstract: We study how human capital and economic conditions causally affect the choice of religious denomination. We utilize a longitudinal dataset monitoring the religious history of more than 5, 000 Kenyans over twenty years, in tandem with a randomized experiment (deworming) that has exogenously boosted education and living standards. The main finding is that the program reduces the likelihood of membership in a Pentecostal denomination up to 20 years later when respondents are in their mid-thirties, while there is a comparable increase in membership in traditional Christian denominations. The effect is concentrated and statistically significant among a sub-group of participants who benefited most from the program in terms of increased education and income. The effects are unlikely due to increased secularization, because the program does not reduce measures of religiosity. The results help explain why the global growth of the Pentecostal movement, sometimes described a "New Reformation", is centered in low-income communities.
    Keywords: religion, identity, human capital, Kenya
    JEL: C93 O12 Z12
    Date: 2023–11
  24. By: Yang, Nanyin; Palma, Marco; Drichoutis, Andreas C.
    Abstract: Virtual assistants powered by artificial intelligence are present in virtually every aspect of daily life. Although they are computer algorithms, most are represented with humanized personal characteristics. We study whether assigning them a gender affects the propensity to delegate a search in two online experiments and compare it to human counterparts of identical characteristics. Virtual assistants generally receive higher delegation than humans. Gender has differential effects in delegation rates impacting the user's welfare. The results are entirely driven by female subjects. We find mild spillover effects, primarily decreasing selection of male humans after interacting with low-quality male virtual assistants.
    Keywords: anthropomorphic features; artificial intelligence; autonomy; delegation; gender;
    JEL: C90 D23 D82 O33
    Date: 2023–11–26
  25. By: Leight, Jessica; Alderman, Harold; Gilligan, Daniel; Hidrobo, Melissa; Mulford, Michael
    Abstract: In recent years, a growing literature has examined the potential of multifaceted, intensive “graduation model†interventions that simultaneously address multiple barriers constraining households’ exit from poverty. In this paper, we present new evidence from a randomized trial of a lighter-touch graduation model implemented in rural Ethiopia. The primary experimental arms are a bundled intervention including a productive transfer valued at $374 (randomly assigned to be cash or an equivalent value in poultry), training, and savings groups; a simpler intervention including training and savings groups only; and a control arm. We find that three years post-baseline, the intervention inclusive of the transfer leads to some increases in assets, savings, and cash income from livestock, though there is no shift in consumption or household food security; these effects are consistent regardless of the modality of the transfer (cash versus poultry). The effects of training and savings groups alone are minimal.
    Keywords: ETHIOPIA; EAST AFRICA; AFRICA SOUTH OF SAHARA; graduation model; households; poverty; cash transfers; poultry; training; savings groups; assets; income; livestock; consumption; food security
    Date: 2023
  26. By: Eiji Yamamura; Yoshiro Tsutsui; Fumio Ohtake
    Abstract: Some people did not get the COVID-19 vaccine even though it was offered at no cost. A monetary incentive might lead people to vaccinate, although existing studies have provided different findings about this effect. We investigate how monetary incentives differ according to individual characteristics. Using panel data with online experiments, we found that (1) subsidies reduced vaccine intention but increased it after controlling heterogeneity; (2) the stronger the social image against the vaccination, the lower the monetary incentive; and (3) persistently unvaccinated people would intend to be vaccinated only if a large subsidy was provided.
    Date: 2023–11

General information on the NEP project can be found at For comments please write to the director of NEP, Marco Novarese at <>. Put “NEP” in the subject, otherwise your mail may be rejected.
NEP’s infrastructure is sponsored by the School of Economics and Finance of Massey University in New Zealand.