Papers - Natural

Alan S Gerber, Donald P Green, Ron Shachar

Cited by*: 39 Downloads*: 19

Habit is a frequently mentioned but understudied cause of political action. This article provides the first direct test of the hypothesis that casting a ballot in one election increases one's propensity to go to the polls in the future. A field experiment involving 25,200 registered voters was conducted prior to the November general election of 1998. Subjects were randomly assigned to treatment conditions in which they were urged to vote through direct mail or face-to-face canvassing. Compared to a control group that received no contact, the treatment groups were significantly more likely to vote in 1998. The treatment groups were also significantly more likely to vote in local elections held in November of 1999. After deriving a statistical estimator to isolate the effect of habit, we find that, ceteris paribus, voting in one election substantially increases the likelihood of voting in the future. Indeed, the influence of past voting exceeds the effects of age and education reported in previous studies.

Colin F Camerer

Cited by*: 23 Downloads*: 19

To test whether naturally occurring markets can be strategically manipulated, $500 and $1,000 bets were made, then cancelled, at horse racing tracks. The net effects of these costless temporary bets give clues about how market participants react to information large bets might contain. The bets moved odds on horses visibly (compared to matched-pair control horses with similar prebet odds) and had a slight tendency to draw money toward the horse that was temporarily bet, but the net effect was close to zero and statistically insignificant. The results suggest that some bettors inferred information from bets and others did not, and their actions roughtly cancelled out.

Alison Booth, Andrew Leigh

Cited by*: 23 Downloads*: 19

We test for gender discrimination by sending fake CVs to apply for entry-level jobs. Female candidates are more likely to receive a callback, with the difference being largest in occupations that are more female-dominated.

Tanjim Hossain, John A List

Cited by*: 9 Downloads*: 19

Recent discoveries in behavioral economics have led to important new insights concerning what can happen in markets. Such gains in knowledge have come primarily via laboratory experiments--a missing piece of the puzzle in many cases is parallel evidence drawn from naturally-occurring field counterparts. We provide a small movement in this direction by taking advantage of a unique opportunity to work with a Chinese high-tech manufacturing facility. Our study revolves around using insights gained from one of the most influential lines of behavioral research--framing manipulations--in an attempt to increase worker productivity in the facility. Using a natural field experiment, we report several insights. For example, conditional incentives framed as both "losses" and "gains" increase productivity for both individuals and teams. In addition, teams more acutely respond to bonuses posed as losses than as comparable bonuses posed as gains. The magnitude of the effect is roughly 1%: that is, total team productivity is enhanced by 1% purely due to the framing manipulation. Importantly, we find that neither the framing nor the incentive effect lose their importance over time; rather the effects are observed over the entire sample period. Moreover, we learn that worker reputation and conditionality of the bonus contract are substitutes for sustenance of incentive effects in the long-run production function.

John A List, Warren McHone , Daniel L Millimet

Cited by*: 11 Downloads*: 19

Whether environmental regulations alter capital flows remains a hotly debated issue. This paper uses county-level data to examine the location decisions of domestic and foreign firms in a single empirical model and tests for asymmetries by firm origin in the degree to which capital flows are influenced by environmental standards. We find that while domestic firms are influenced by environmental regulations, foreign firms are not. Since the benefits of foreign investment are well-documented-foreign plants typically provide more jobs and increase local wages by more than domestic plants-this result suggests a double-dividend is available: foreign plants provide an economic stimulus and are not unduly influenced by environmental protections.

Paul Glewwe, Albert Park, Meng Zhao

Cited by*: 2 Downloads*: 19

About 10% of primary school students in developing countries have poor vision, yet in virtually all of these countries very few children wear glasses. There has been almost no research on the impact of poor vision on school performance in developing countries, and simple OLS estimates are likely to be biased because students who study more often are likely to develop poor vision faster. This paper presents results from a randomized trial in Western China that began in the summer of 2004. The trial involves over 19,000 students in 165 schools in two counties of Gansu province. The schools were randomly divided (at the township level) into 103 schools that received eyeglasses (for students in grades 4-6) and 62 schools that served as controls. The results indicate that, after one year, making eyeglasses available increased average test scores by 0.11 to 0.15 standard deviations (of the distribution of the test scores). For those students who accepted the glasses, average test scores increased by 0.15 to 0.22 standard deviations.

Michael Kremer, Edward Miguel

Cited by*: 16 Downloads*: 19

We examine social learning using data from a program that promoted use of deworming medicine in Kenyan schools. These drugs kill worms in the body; although people are soon reinfected, treatment interferes with the cycle of transmission, generating positive externalities. Individuals randomly exposed to more information about deworming drugs through their social network were significantly less likely to take the drugs and more likely to believe the drugs are "not effective." This finding is consistent with the hypothesis that those exposed to the program had overly optimistic prior beliefs about net private drug benefits. The combination of strong social effects and extensive social networks among teenagers implies that a "child-to-child" public health approach focused on teenagers will speed social learning. There are large differences between social effect estimates relying on experimental variation (negative estimates) and nonexperimental methods (positive estimates).

Carina Cavalcanti, Andreas Leibbrandt

Cited by*: 0 Downloads*: 18

This paper investigates the role of dry promotions for community participation in eight Brazilian fishing villages. We randomly promoted some fishermen to assistants before the start of an environmental program, increasing their responsibilities but not providing any monetary compensation. Thereafter, we study whether they engage more in conservation behavior during this program. The data shows that promoted fishermen provide substantially more effort, which suggests that such promotions my be a cost-effective tool to stimulate cooperation and community participation.

Per Fredriksson , John A List, Daniel L Millimet

Cited by*: 33 Downloads*: 18

Previous studies have proposed that equilibrium capital flows are affected by environmental regulations-the commonly coined 'pollution haven' hypothesis. We revisit this issue by treating environmental policies as endogenous and allowing governmental corruption to influence foreign direct investment patterns. Via these two simple extensions, we are able to provide a much richer model of international capital flows. The theoretical model presumes that the effect of corruption on FDI operates via two channels: corruption affects capital flows through its impact on environmental policy stringency and due to greater theft of public funds earmarked for public spending. We empirically examine the implications of the model using US state-level panel data from four industrial sectors over the period 1977-1987. Empirical results suggest environmental policy and corruption both play a significant role in determining the spatial allocation of inbound US FDI. In addition, the estimated effect of environmental policy is found to depend critically on exogeneity assumptions.

Ginger Z Jin, Andrew Kato

Cited by*: 2 Downloads*: 18

Every new method of trade offers an opportunity for economic agents to compare its costs and benefits relative to the status quo. Such comparison motivates sorting across market segments and reshapes the whole marketplace. The Internet provides an excellent example: it introduces substantial search cost savings over brick and mortar retail stores but imposes new obstacles for sellers to convey quality. Using sports card trading as a case study, we provide empirical evidence on (1) the sorting of product quality between the online and offline segments, (2) the changes for retail outlets after the Internet came into place, and (3) how supporting industries such as professional grading and card manufacturing adapted to take advantage of the new market.

Mirco Tonin, Michael Vlassopoulos

Cited by*: 3 Downloads*: 18

This paper presents evidence from a field experiment, which aims to identify the two sources of workers' pro-social motivation that have been considered in the literature: action-oriented altruism and output-oriented altruism. To this end we employ an experimental design that first measures the level of effort exerted by student workers on a data entry task in an environment that elicits purely selfish behavior and we compare it to effort exerted in an environment that also induces action-oriented altruism. We then compare the latter to effort exerted in an environment where both types of altruistic preferences are elicited. We find that action-oriented altruism accounts for a significant increase in effort, while there is no additional impact due to output-oriented altruism. We also find significant gender-related differences in the treatment effect: women are very responsive to the treatment condition eliciting action-oriented altruism, while men's behavior is not affected by any of the treatments.

Anya Samek, Roman Sheremeta

Cited by*: 0 Downloads*: 18

Recognizing donors by revealing their identities is important for increasing charitable giving. We conducted a field experiment to examine how different recognition methods impact giving, and found that all forms of recognition that we examined had a positive impact on increasing donations, whereby recognizing only highest donors (positive recognition) and recognizing only lowest donors (negative recognition) had the most pronounced effect. We argue that selective recognition (both positive and negative) creates tournament-like incentives. Recognizing the highest donors activates the desire to seek a positive prize of prestige, thus increasing the proportion of donors who contribute large amounts. Recognizing the lowest donors activates the desire to avoid a negative prize of shame, thus decreasing the proportion of donors who do not contribute or contribute very little. Therefore, selective recognition is an effective tool that can be used in the field by charities to increase donations.

Laura Derksen, Adamson Muula, Joep van Oosterhout

Cited by*: 0 Downloads*: 18

The HIV epidemic in southern Africa has important consequences for economic development. The epidemic could be stopped by a universal test and treat policy, as antiretroviral drugs block the spread of the virus. However, demand for HIV testing and treatment are surprisingly low. This paper develops a model in which the decision to seek an HIV test is a signal of infection, and those who seek a test are subject to statistical discrimination from potential sexual partners. We evaluate an information experiment designed to test the theory, and find evidence that this form of discrimination is a significant barrier to HIV testing. In particular, we provide information at the community level on the public benefit of antiretroviral therapy: because the drugs prevent HIV transmission, a person who is tested and treated for HIV is a relatively safe sexual partner. This information reduces discrimination and increases HIV testing, with the strongest effects in communities where the new information becomes common knowledge. The results demonstrate that discrimination towards HIV positive individuals can be due to rational behavior by a misinformed public, and that providing new information can be an effective way to mitigate its effects.

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.

Dean S Karlan, Jonathan Zinman

Cited by*: 5 Downloads*: 17

Expanding access to commercial credit is a key ingredient of financial development strategies. There is less consensus on whether expanding access to consumer credit helps borrowers, particularly when loans are extended at high interest rates. Popular skepticism about "unproductive," "usurious" lending is fueled by research highlighting behavioral biases that may induce overborrowing. We estimate the impacts of expanding access to consumer credit at a 200% annual percentage rate (APR) using a field experiment and follow-up data collection. The randomly assigned marginal loans produced significant net benefits for borrowers across a wide range of outcomes. There is also some evidence that the loans were profitable.

Armin Falk

Cited by*: 8 Downloads*: 17

This study reports data from a field experiment that was conducted to investigate the relevance of gift-exchange for charitable giving. Roughly 10,000 solicitation letters were sent to potential donors in the experiment. One third of the letters contained no gift, one third contained a small gift and one third contained a large gift. Whether a potential donor received a letter with or without a gift was randomly determined. We observe strong and systematic effects from including gifts. Compared to the no gift condition, the relative frequency of donations increased by 17 percent if a small gift was included and by 75 percent for a large gift. Consequently, including gifts was highly profitable for the charitable organization. The contribution of this paper is twofold: first, it shows that gift-exchange is important for charitable giving, in addition to the warm-glow motive. Second, the paper confirms the economic relevance of reciprocity by using field data. This extends the current body of research on reciprocity, which is almost exclusively confined to laboratory studies.

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.

Paul W Rhode, Koleman S Strumpf

Cited by*: 12 Downloads*: 16

Political stock markets have a long history in the United States. Organized prediction markets for Presidential elections have operated on Wall Street (1880-1944), the Iowa Electronic Market (1988-present), and TradeSports (2001-present). Proponents claim such markets efficiently aggregate information and provide forecasts superior to polls. An important counterclaim is that such markets may be subject to manipulation by interested parties. We analyze this argument by studying alleged and actual speculative attacks- large trades, uninformed by fundamentals, intended to change prices- in these three markets. We first examine the historical Wall Street markets where political operatives from the contending parties actively and openly bet on city, state and national races; the record is rife with accusations that parties tried to boost their candidates through investments and wash bets. Next we report the results of a field experiment involving a series of planned, random investments-- accounting for two percent of total market volume-- in the Iowa Electronic Market in 2000. Finally, we investigate the speculative attacks on TradeSports market in 2004 when a single trader made a series of large investments in an apparent attempt to make one candidate appear stronger. In the cases studied here, the speculative attack initially moved prices, but these changes were quickly undone and prices returned close to their previous levels. We find little evidence that political stock markets can be systematically manipulated beyond short time periods.

Paul Glewwe, Michael Kremer, Sylvie Moulin, Eric Zitzewitz

Cited by*: 42 Downloads*: 16

This paper compares retrospective and prospective analyses of the effect of flip charts on test scores in rural Kenyan schools. Retrospective estimates that focus on subjects for which flip charts are used suggest that flip charts raise test scores by up to 20 percent of a standard deviation. Controlling for other educational inputs does not reduce this estimate. In contrast, prospective estimators based on a study of 178 schools, half of which were randomly selected to receive charts, provide no evidence that flip charts increase test scores. One interpretation is that the retrospective results were subject to omitted variable bias despite the inclusion of control variables. If the direction of omitted variable bias were similar in other retrospective analyses of educational inputs in developing countries, the effects of inputs may be even more modest than retrospective studies suggest. Bias appears to be reduced by a differences-in-differences estimator that examines the impact of flip charts on the relative performance of students in flip chart and other subjects across schools with and without flip charts, but it is not clear that this approach is applicable more generally.

Dean S Karlan, Jonathan Zinman

Cited by*: 4 Downloads*: 16

The price elasticity of demand for credit has major implications for macroeconomics, finance, and development. We present estimates of this parameter derived from a randomized trial. The experiment was implemented by a consumer microfinance lender in South Africa and identifies demand curves that, while downward-sloping with respect to price, are flatter than recent estimates in both developing and developed countries throughout most of a wide price range. However, demand becomes highly price sensitive at higher-than-normal rates. We discuss several interpretations of this kink and present some related evidence. We also find that loan size is far more responsive to changes in loan maturity than to changes in interest rate. This pattern is more pronounced among lower income individuals, a comparative static that has been observed in the United States as well and is consistent with liquidity constraints that decrease with income.