Papers - Natural

Stephan Meier

Cited by*: 2 Downloads*: 20

Framing a decision situation differently has affected behavior substantially in previous studies. This paper tests a framing effect in a field experiment at the University of Zurich. Each semester, every student has to decide whether to contribute to two social funds. Students were randomly informed that a high percentage of the student population contributed (or, equivalently, that a low percentage did not contribute), while others received the information that a relatively low percentage contributed (or a high percentage did not contribute). The results show the influence of framing effects is limited. People behave in a conditional cooperative way if informed either about the number of contributors or about the equivalent number of non-contributors. The positive correlation between group behavior and individual behavior is, however, weaker when the focus is on the defectors. The field experiment also shows gender differences in social comparison.

John A List

Cited by*: 262 Downloads*: 100

This study examines individual behavior in two well-functioning marketplaces to investigate whether market experience eliminates the endowment effect. Field evidence from both markets suggests that individual behavior converges to the neoclassical prediction as market experience increases. In an experimental test of whether these observations are due to treatment (market experience) or selection (e.g., static preferences), I find that market experience plays a significant role in eliminating the endowment effect. I also find that these results are robust to institutional change and extend beyond the two marketplaces studied. Overall, this study provides strong evidence that market experience eliminates an important market anomaly.

Dean S Karlan, John A List

Cited by*: 37 Downloads*: 17

We conducted a natural field experiment to explore the effect of price changes on charitable contributions. To operationalize our tests, we examine whether an offer to match contributions to a non-profit organization changes the likelihood and amount that an individual donates. Direct mail solicitations were sent to over 50,000 prior donors. We find that the match offer increases both the revenue per solicitation and the probability that an individual donates. While comparisons of the match treatments and the control group consistently reveal this pattern, larger match ratios (i.e., $3:$1 and $2:$1) relative to smaller match ratios ($1:$1) had no additional impact. The results have clear implications for practitioners in the design of fundraising campaigns and provide avenues for future empirical and theoretical work on charitable giving. Further, the data provide an interesting test of important methods used in cost-benefit analysis.

Amanda Bayer, Syon Bhanot, Fernando Lozano

Cited by*: None Downloads*: None

No abstract available

Gad Allon, Jan A. Van Mieghem, Dennis J. Zhang

Cited by*: 0 Downloads*: 71

This paper studies how service providers can design social interaction among participants and quantify the causal impact of that interaction on service quality. We focus on education and analyze whether encouraging social interaction among students improves learning outcomes in Massive Open Online Courses (MOOCs), which are a new service delivery channel with universal access at reduced, if not zero, cost. We analyze three randomized experiments in a MOOC with more than 30; 317 students from 183 countries. Two experiments study large-group interaction by encouraging a random subset of students to visit the course discussion board. The majority of students treated in these experiments had higher social engagement, higher quiz completion rates, and higher course grades. Using these treatments as instrumental variables, we estimate that one additional board visit causally increases the probability that a student finishes the quiz in the subsequent week by up to 4:3%. The third experiment studies small-group interaction by encouraging a random subset of students to conduct one-on-one synchronous discussions. Students who followed through and actually conducted pairwise discussions increased their quiz completion rates and quiz scores by 10% in the subsequent week. Combining results from these three experiments, we provide recommendations for designing social interaction mechanisms to improve service quality.

Daniel Bergan, Alan S Gerber, Dean S Karlan

Cited by*: 36 Downloads*: 27

We conducted a field experiment to measure the effect of exposure to newspapers on political behavior and opinion. Before the 2005 Virginia gubernatorial election, we randomly assigned individuals to a Washington Post free subscription treatment, a Washington Times free subscription treatment, or a control treatment. We find no effect of either paper on political knowledge, stated opinions, or turnout in post-election survey and voter data. However, receiving either paper led to more support for the Democratic candidate, suggesting that media slant mattered less in this case than media exposure. Some evidence from voting records also suggests that receiving either paper led to increased 2006 voter turnout.

Chris Arnot, Peter C Boxall, Sean B Cash

Cited by*: 43 Downloads*: 54

The existing literature on socially responsible purchasing relies heavily on stated preference measures elicited through surveys that utilize hypothetical market choices. This paper explores consumers' revealed purchasing behavior with regard to fair trade coffee and is apparently the first to do so in an actual market setting. In a series of experiments, we investigated differences in consumer responsiveness to relative price changes in fair trade and non-fair trade brewed coffees. In order to minimize the hypothetical bias that may be present in some experimental settings, we conducted our experiments in cooperation with a vendor who allowed us to vary prices in an actual coffee shop. Using a choice model, we found that purchasers of fair trade coffee were much less price responsive than those of other coffee products. The demonstration of low sensitivity to price suggests that the market premiums identified by stated preference studies do indeed exist and are not merely artifacts of hypothetical settings.

John A List

Cited by*: 117 Downloads*: 34

No abstract available

Kosuke Imai

Cited by*: 12 Downloads*: 9

In their landmark study of a field experiment, Gerber and Green (2000) found that get-out-the-vote calls reduce turnout by five percentage points. In this article, I introduce statistical methods that can uncover discrepancies between experimental design and actual implementation. The application of this methodology shows that Gerber and Green's negative finding is caused by inadvertent deviations from their stated experimental protocol. The initial discovery led to revisions of the original data by the authors and retraction of the numerical results in their article. Analysis of their revised data, however, reveals new systematic patterns of implementation errors. Indeed, treatment assignments of the revised data appear to be even less randomized than before their corrections. To adjust for these problems, I employ a more appropriate statistical method and demonstrate that telephone canvassing increases turnout by five percentage points. This article demonstrates how statistical methods can find and correct complications of field experiments.

Amanda Kowalski

Cited by*: 4 Downloads*: 6

I examine treatment effect heterogeneity within an experiment to inform external validity. The local average treatment effect (LATE) gives an average treatment effect for compliers. I bound and estimate average treatment effects for always takers and never takers by extending marginal treatment effect methods. I use these methods to separate selection from treatment effect heterogeneity, generalizing the comparison of OLS to LATE. Applying these methods to the Oregon Health Insurance Experiment, I find that the treatment effect of insurance on emergency room utilization decreases from always takers to compliers to never takers. Previous utilization explains a large share of the treatment effect heterogeneity. Extrapolations show that other expansions could increase or decrease utilization.

Michel Marechal, Christian Thoni

Cited by*: 10 Downloads*: 16

A substantive amount of lab experimental evidence suggests that the norm of reciprocity has important economic consequences. However, it is unclear whether the norm of reciprocity survives in a natural and competitive environment with experienced agents. For this purpose we analyze data from a natural field experiment conducted with sales representatives who were instructed to randomly distribute product samples as gifts to their business partners. We find that distributing gifts to store managers boosts sales revenue substantially, which is consistent with the notion of reciprocity. However, the results underline that the nature of the relationship between market participants crucially affects the prevalence of reciprocal behavior.

Omar Al-Ubaydli, John A List

Cited by*: 5 Downloads*: 89

A commonly held view is that laboratory experiments provide researchers with more "control" than natural field experiments, and that this advantage is to be balanced against the disadvantage that laboratory experiments are less generalizable. This paper presents a simple model that explores circumstances under which natural field experiments provide researchers with more control than laboratory experiments afford. This stems from the covertness of natural field experiments: laboratory experiments provide researchers with a high degree of control in the environment which participants agree to be experimental subjects. When participants systematically opt out of laboratory experiments, the researcher's ability to manipulate certain variables is limited. In contrast, natural field experiments bypass the participation decision altogether and allow for a potentially more diverse participant pool within the market of interest. We show one particular case where such selection is invaluable: when treatment effects interact with participant characteristics.

Alan S Gerber, Donald P Green

Cited by*: 12 Downloads*: 13

No abstract available

Maria P Espinosa, Javier Gardeazabal

Cited by*: 2 Downloads*: 43

A disadvantage of multiple-choice tests is that students have incentives to guess. To discourage guessing, it is common to use scoring rules that either penalize wrong answers or reward omissions. These scoring rules are considered equivalent in psychometrics, although experimental evidence has not always been consistent with this claim. We model students' decisions and show, first, that equivalence holds only under risk neutrality and, second, that the two rules can be modified so that they become equivalent even under risk aversion. This paper presents the results of a filed experiment in which we analyze the decisions of subjects taking multiple-choice exams. The evidence suggests that differences between scoring rules are due to risk aversion as theory predicts. We also find that the number of omitted items depends on the scoring rule, knowledge, gender, and other covariates.

Stephan Meier

Cited by*: 0 Downloads*: 8

Subsidizing charitable giving-for example, for victims of natural disasters-is very popular, not only with governments but also with private organizations. Many companies match their employees' charitable contributions, hoping that this will foster the willingness to contribute. However, systematic analyses of the effect of such a matching mechanism are still lacking. This article tests the effect of matching charitable giving in a randomized field experiment in the short and the long run. The donations of a randomly selected group were matched by contributions from an anonymous donor. The results support the hypothesis that a matching mechanism increases contributions to a public good. However, in the periods after the experiment, when matching donations have been stopped, the contribution rate declines for the treatment group. The matching mechanism leads to a negative net effect on the participation rate. The field experiment therefore provides evidence suggesting that the willingness to contribute may be undermined by a matching mechanism in the long run.

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

Cited by*: 4 Downloads*: 95

This study examines the mechanisms underlying long-run reductions in energy consumption caused by a widely studied social nudge. Our investigation considers two channels: physical capital in the home and habit formation in the household. Using data from 38 natural field experiments, we isolate the role of physical capital by comparing treatment and control homes after the original household moves, which ends treatment. We find 35 to 55 percent of the reductions persist once treatment ends and show this is consonant with the physical capital channel. Methodologically, our findings have important implications for the design and assessment of behavioral interventions.

Andreas Leibbrandt, John A List

Cited by*: 7 Downloads*: 74

One explanation advanced for the persistent gender pay differences in labor markets is that women avoid salary negotiations. By using a natural field experiment that randomizes nearly 2,500 job-seekers into jobs that vary important details of the labor contract, we are able to observe both the nature of sorting and the extent of salary negotiations. We observe interesting data patterns. For example, we find that when there is no explicit statement that wages are negotiable, men are more likely to negotiate than women. However, when we explicitly mention the possibility that wages are negotiable, this difference disappears, and even tends to reverse. In terms of sorting, we find that men in contrast to women prefer job environments where the 'rules of wage determination' are ambiguous. This leads to the gender gap being much more pronounced in jobs that leave negotiation of wage ambiguous.

Maria De Paola, Rosetta Lombardo, Valeria Pupo, Vincenzo Scoppa

Cited by*: None Downloads*: None

Public speaking is an important skill for career prospects and for leadership positions, but many people tend to avoid it because it generates anxiety. We run a field experiment to analyze whether in an incentivized setting men and women show differences in their willingness to speak in public. The experiment involved more than 500 undergraduate students who could gain two points to add to the final grade of their exam by presenting solutions to a problem set. Students were randomly assigned to present only to the instructor or in front of a large audience (a class of 100 or more). We find that while women are more willing to present face-to-face, they are considerably less likely to give a public presentation. Female aversion to public speaking does not depend on differences in ability, risk aversion, self-confidence and self-esteem. The aversion to public speaking greatly reduces for daughters of working women. From data obtained through an on-line Survey we also show that neither increasing the gains deriving from public speaking nor allowing participants more time to prepare enable to close the gender gap.

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.

Ernst Fehr, Lorenz Goette

Cited by*: 62 Downloads*: 31

Abstract: Most previous studies on intertemporal labor supply found very small or insignificant substitution effects. It is not clear, however, whether these results are due to institutional constraints on workers' labor supply choices or whether the behavioral assumptions of the standard life cycle model with time separable preferences are empirically invalid. We conducted a randomized field experiment in a setting in which workers were free to choose their working times and their efforts during working time. We document a large positive wage elasticity of overall labor supply and an even larger wage elasticity of labor hours, which implies that the wage elasticity of effort per hour is negative. While the standard life cycle model cannot explain the negative effort elasticity, we show that a modified neoclassical model with preference spillovers across periods and a model with reference dependent, loss averse preferences are consistent with the evidence. With the help of a further experiment we can show that only loss averse individuals exhibit a significantly negative effort response to the wage increase and that the degree of loss aversion predicts the size of the negative effort response.