Papers - Natural

Matilde Giaccherini, David H Herberich, David Jimenez-Gomez, John A List, Giovanni Ponti, Michael K Price

Cited by*: None Downloads*: None

This paper uses a field experiment to estimate the effects of prices and social norms on the decision to adopt and efficient technology. We find that prices and social norms influence the adoption and decision along different margins: while prices operate on both the extensive and intensive margins, social norms operate mostly through the extensive margin. This has both positive and normative implications, and suggests that economics and psychology may be strong complements in the diffusion process. To complement the reduced form results, we estimate a structural model that points to important household heterogeneity: whereas some consumers welcome the opportunity to purchase and learn about the new technology, for others the inconvenience and social pressure of the ask results in negative welfare. As a whole, our findings highlight that the design of optimal technological diffusion policies will require multiple instruments and a recognition of household heterogeneity.

Indranil Goswami, Oleg Urminsky

Cited by*: None Downloads*: None

How does setting a donation option as the default in a charitable appeal affect people's decisions? In eight studies, comprising 11,508 participants making 2,423 donation decisions in both experimental settings and a large scale-natural field experiment, we investigate the effect of "choice-option" defaults on the donation rate, average donation amount, and the resulting revenue. We find (1) a "lower-bar" effect, where defaulting a low amount increases donation rate, (2) a "scale-back" effect where low defaults reduce average donation amounts and (3) a "default-distraction' effect, where introducing any defaults reduces the effect of other cues, such as positive charity information. Contrary to the view that setting defaults will backfire, defaults increased revenue in our field study. However, our findings suggest that defaults can sometimes be a "self-cancelling" intervention, with countervailing effects of default option magnitude on decisions and resulting in no net effect on revenue. We discuss the implications of our findings for research on fundraising specifically, for choice architecture and behavioral interventions more generally, as well as for the use of "nudges" in policy decisions.

Haoran He, David Neumark, Qian Weng

Cited by*: None Downloads*: None

We explore compensating differentials for job flexibility, using a field experiment conducted on a Chinese job board. Our job ads differ randomly regarding when one works (time flexibility) and where one works (place flexibility). We find strong evidence that workers value job flexibility - especially regarding place of work. Application rates are higher to flexible jobs, conditional on the salary offered. Additional survey evidence indicates that workers are willing to take lower pay for more flexible jobs. Non-experimental job board data do not indicate that workers value job flexibility, reinforcing the difficulty of estimating compensating differentials from observational data.

Michal Krawczyk, Joanna Rachubik

Cited by*: None Downloads*: None

Despite having the same probability of being drawn, certain number combinations are more popular than others among the lottery players. One explanation of such preferences is the representativeness heuristic (RH). Unlike previous hypothetical experiments, in the present experiment we used real-life lottery tickets, involving a high payout in case of winning to elicit true preferences. To verify if people prefer randomly-looking number combinations, participants were to choose a preferred ticket. To validate if it is likely to be caused by RH, we correlated preference for "random" sequences with the belief in dependence between subsequent coin tosses. We confirm that people strongly prefer random sequences and that a non-trivial fraction believes in dependence between coin tosses. However, there is no correlation between these two tendencies, questioning the RH explanation. By contrast, participants who have an (irrationally) strong preference for number combinations also tend to make (irrationally) specific predictions in the coin task. Unexpectedly, we find that females are considerably more likely to belong to this groups than males.

Erwin Bulte, John A List, Daan van Soest

Cited by*: None Downloads*: None

Social scientists have recently explored how framing of gains and losses affects productivity. We conducted a field experiment in peri-urban Uganda, and compared output levels across 1000 workers over isomorphic tasks and incentives, framed as either losses or gains. We find that loss aversion can be leveraged to increase the productivity of labor. The estimated welfare costs of using the loss contract are quite modest -- perhaps because the loss contract is viewed as a (soft) commitment device.

Omar Al-Ubaydli, John A List

Cited by*: None Downloads*: None

This is a review of the literature of field experimental studies of markets. The main results covered by the review are as follows: (1) Generally speaking, markets organize the efficient exchange of commodities; (2) There are some behavioral anomalies that impede efficient exchange; (3) Many behavioral anomalies disappear when traders are experienced.

John A List

Cited by*: None Downloads*: None

This review summarizes the historical place of the seminal contribution of Kahneman et al. (1990), from origins to theory to catalyst of an entire area of scholarship. This new literature has produced evidence both in concert with the original KKT conclusions as well as evidence refuting certain insights from KKT. The general theme of my summary is that even imperfect papers can have deep impact, both within and outside the academy; a lesson that today's critics should consider as young experimentalists continue to fight the tyranny of the top 5.

Basil Halperin, Benjamin Ho, John A List, Ian Muir

Cited by*: None Downloads*: None

We use a theory of apologies to analyze a nationwide field experiment involving 1.5 million Uber ridesharing consumers who experienced late rides. Several insights emerge. First, apologies are not a panacea: the efficacy of an apology and whether it may backfire depend on how the apology is made. Second, across treatments, money speaks louder than words - the best form of apology is to include a coupon for a future trip. Third, in some cases sending an apology is worse than sending nothing at all, particularly for repeated apologies. For firms, caveat venditor should be the rule when considering apologies.

Ran Kivetz, Oleg Urminsky, Yuhuang Zheng

Cited by*: None Downloads*: None

The goal-gradient hypothesis denotes the classic finding from behaviorism that animals expend more effort as they approach a reward. Building on this hypothesis, the authors generate new propositions for the human psychology of rewards. They test these propositions using a field experiment, secondary customer data, paper-and-pencil problems, and Tobit and logit models. The key finding indicate that (1) participants in a real cafe reward program purchase coffee more frequently the closer they are to earning a free coffee; (2) Internet users who rate songs in return for reward certificates visit the rating Web site more often, rate more songs per visit, and persist longer in the rating effort as they approach the reward goal; (3) the illusion of progress toward the goal induces purchase acceleration (e.g., customers who receive a 12-stamp coffee card with 2 preexisting "bonus" stamps complete the 10 required purchases faster than customers who receive a "regular" 10-stamp card) and (4) a stronger tendency to accelerate toward the goal predicts greater retention and faster reengagement in the program. The conceptualization and empirical findings are captured by a parsimonious goal distance model, in which effort investment is a function of the proportion of original distance remaining to the goal. In addition, using statistical and experimental controls, the authors rule out alternative explanations for the observed goal gradients. They discuss the theoretical significance of their findings and the managerial implications for incentive systems, promotions, and customer retention.

Alec Brandon, John A List, Robert D Metcalfe, Michael K Price, Florian Rundhammer

Cited by*: None Downloads*: None

This study considers the response of household electricity consumption to social nudges during peak load events. Our investigation considers two social nudges. The first targets conservation during peak load events, while the second promotes aggregate conservation. Using data from a natural field experiment with 42,100 households, we find that both social nudges reduce peak load electricity consumption by 2 to 4% when implemented in isolation and by nearly 7% when implemented in combination. These findings suggest an important role for social nudges in the regulation of electricity markets and a limited role for crowd out effects.

Syon Bhanot

Cited by*: None Downloads*: None

Social norms messaging campaigns are increasingly used to influence human behavior, with social science research generally finding that they have modest but meaningful effects. One aspect of these campaigns in practice has been the inclusion of injunctive norms messaging, designed to convey a social judgement about one's behaviors (often in the form of encouraging or discouraging language, or a visual smiley or frowny face). While some prominent research has provided support for the use of such messaging as a tool for positive behavior change, causal evidence on the effect of injunctive norms messaging as a motivator (as opposed to just one part of a multifaceted messaging campaign) is limited. This paper presents a field experiment on water conservation behavior conducted by an organization in California, involving over 40,000 households, which provides some of the most precise evidence to date regarding the effect of injunctive norms on decision making. I find that not only do injunctive norms encourage conservation behavior, there is also no evidence that they discourage individuals from further attending norms messaging-regardless of whether the social judgement conveyed is negative or positive. Taken together, this suggests that injunctive norms are a useful tool in "nudge"-style campaigns tackling behavior change.

Eliot Abrams, Jonathan Libgober, John A List

Cited by*: None Downloads*: None

The past few decades have ushered in an experimental revolution in economics whereby scholars are now much more likely to generate their own data. While there are virtues associated with this movement, there are concomitant difficulties. Several scientific disciplines, including economics, have launched research registries in an effort to attenuate key inferential issues. This study assesses registries both empirically and theoretically, with a special focus on the AEA registry. We find that over 90% of randomized controlled trials (RCTs) in economics do not register, only 50% of the RCTs that register do so before the intervention begins, and the majority of these preregistrations are not detailed enough to significantly aid inference. Our empirical analysis further shows that using other scientific registries as aspirational examples is misguided, as their perceived success in tackling the main issues is largely a myth. In light of these facts, we advance a simple economic model to explore potential improvements. A key insight from the model is that removal of the (current) option to register completed RCTs could increase the fraction of trials that register. We also argue that linking IRB applications to registrations could further increase registry effectiveness.

Alexander G James, John A List, James J Murphy, Michael K Price

Cited by*: None Downloads*: None

We partnered with Alaska's Pick.Click.Give. Charitable Contributions Program to implement a statewide natural field experiment with 540,000 Alaskans designed to explore whether targeted appeals emphasizing donor benefits through warm glow impact donations. Results highlight the relative import of appeals to self. Individuals who received such an appeal were 4.5 percent more likely to give and gave 20 percent more than counterparts in the control group. Yet, a message that instead appealed to recipient benefits had no effect on average donations relative to the control group. We also find evidence of long-run effects of warm glow appeals in the subsequent year.

Pradhi Aggarwal, Alec Brandon, Ariel Goldszmidt, Justin Holz, John A List, Ian Muir, Gregory Sun, Thomas Yu

Cited by*: None Downloads*: None

Prior research finds that, conditional on an encounter, minority civilians are more likely to be punished by police than white civilians. An open question is whether the actual encounter is related to race. Using high-frequency location data of rideshare drivers operating on the Lyft platform in Florida, we estimate the effect of driver race on traffic stops and fines for speeding. Estimates obtained across traditional and machine learning approaches show that, relative to a white driver traveling the same speed, minorities are 24 to 33 percent more likely to be stopped for speeding and pay 23 to 34 percent more in fines. We find no evidence that these estimates can be explained by racial differences in accident and re-offense rates. Our study provides key insights into the total effect of civilian race on outcomes of interest and highlights the potential value of private sector data to help inform major social challenges.

Greg Allenby, Russell Belk, Catherine Eckel, Robert Fisher, Ernan Haruvy, John A List, Yu Ma, Peter Popkowski Leszczyc, Yu Wang, Sherry Xin Li

Cited by*: None Downloads*: None

We offer a unified conceptual, behavioral, and econometric framework for optimal fundraising that deals with both synergies and discrepancies between approaches from economics, consumer behavior, and sociology. The purpose is to offer a framework that can bridge differences and open a dialogue between disciplines in order to facilitate optimal fundraising design. The literature is extensive, and our purpose is to offer a brief background and perspective on each of the approaches, provide an integrated framework leading to new insights, and discuss areas of future research.

Mohammad Abdul Malek, Nusrat Abedin Jimi, Subal Kumbhakar, Plamen Nikolov

Cited by*: None Downloads*: None

Improving productivity among farm enterprises is important, especially in low-income countries where market imperfections are pervasive and resources are scarce. Relaxing credit constraints can increase the productivity of farmers. Using a field experiment involving in Bangladesh, we estimated the impact of access to credit on the overall productivity of rice farmers, and disentangled the total effect into technological change (frontier shift) and technical efficiency changes. We found that relative to the baseline rice output per decimal, access to credit resulted in, on average, approximately a 14 percent increase in yield, holding all other inputs constant. After decomposing the total effect into the frontier shift and efficiency improvement, we found that, on average, around 11 percent of the increase in output came from changes in technology, or frontier shift, while the remaining 3 percent was attributed to improvements in technical efficiency. The efficiency gain was higher for modern hybrid rice varieties, and almost zero for traditional rice varieties. Within the treatment group, the effect was greater among pure tenant and mixed-tenant farm households compared with farmers than only cultivated their own land.

Maria De Paola, Francesca Gioia, Vincenzo Scoppa

Cited by*: None Downloads*: None

We ran a field experiment to investigate whether individual performance in teams depends on the gender of the leader. About 430 students from an Italian University took an intermediate exam that was partly evaluated on the basis of teamwork. Students were randomly matched in teams of three and in each team we randomly chose a leader with the task of coordinating the work of the team. We find a positive and significant effect of female leadership on team performance. This effect is driven by the higher performance of team members in female led teams rather than due to an improvement in the leader's performance. We also find that, in spite of the higher performance of female led teams, male members tend to evaluate female leaders as less effective, whereas female members are more sympathetic towards them.

Kuan-Ming Chen, Min Ding, John A List, Magne Mogstad

Cited by*: None Downloads*: None

Recent changes in labor arrangements have increased interest in estimating and understanding the value of job flexibility. We leverage a large natural field experiment at Uber to create exogenous variation in expected market wages across individuals and over time. Combining this experiment with high frequency panel data on wages and individual work decisions, we document how labor supply responds to exogenous changes in expected market wages in a setting with virtually no restrictions on drive labor allocation. We find that there is i) systematic heterogeneity in labor supply responses both across drivers and within a driver over time, ii) significant fixed costs of beginning a shift, and iii) high rider demand when it is costly for drivers to work. These three findings motivate a model of labor supply with heterogeneous preferences over work schedules, adjustment costs, and statistical dependence between market wages and the costs of driving. We recover the labor supply elasticities and reservation wages of this dynamic labor supply model via a combination of experimental estimates and other data moments. We then perform counterfactual analyses that allow us to examine how preference heterogeneity and adjustment costs influence the responses of workers' to wage incentives as well as infer drivers' willingness to pay for the ability to customize and adjust their work schedule. We also show that a static approach to the driver's dynamic problem delivers materially different estimates of workers' labor supply elasticities and their value of job flexibility.

Bharat Chandar, Ali Hortacsu, John A List, Ian Muir, Jeffrey M Wooldridge

Cited by*: None Downloads*: None

Field experiments conducted with the village, city, state, region, or even country as the unit of randomization are becoming commonplace in the social sciences. While convenient, subsequent data analysis may be complicated by the constraint on the number of clusters in treatment and control. Through a battery of Monte Carlo simulations, we examine best practices for estimating unit-level treatment effects in cluster-randomized field experiments, particularly in settings that generate short panel data. In most settings we consider, unit-level estimation with unit fixed effects and cluster-level estimation weighted by the number of units per cluster tend to be robust to potentially problematic features in the data while giving greater statistical power. Using insights from our analysis, we evaluate the effect of a unique field experiment: a nationwide tipping field experiment across markets on the Uber app. Beyond the import of showing how tipping affects aggregate outcomes, we provide several insights on aspects of generating and analyzing cluster-randomized experimental data when there are constraints on the number of experimental units in treatment and control.

Stefano Carattini, Robert Dur, John A. List

Cited by*: None Downloads*: None

Many policies that are generally considered socially desirable by the scientific community, based on modeling and causal empirical analyses, are not very widespread. The main driver is often lack of public support at baseline ("ex ante"). Yet, there is evidence that when voters hold biased beliefs ex ante about a given policy, experiencing the policy firsthand may lead them to correct their beliefs and increase public support. If it was widely documented that opposition to sound policies in part dissipates when voters experience a given policy, then more policy-makers may be inclined to experiment with policies that scientists recommend but that are unpopular ex ante. Systematically combining policy evaluation with causal analysis of public support would allow scholars to create a body of knowledge on the conditions under which policies become more (or less) popular after implementation and what are the drivers of changes in beliefs and public support.