This special issue highlights an empirical approach that has increasingly grown in prominence in the last decade—field experiments. While field experiments can be used quite generally in economics—to test theories’ predictions, to measure key parameters, and to provide insights into the generalizability of empirical results— this special issue focuses on using field experiments to explore questions within the economics of charity. The issue contains six distinct field experimental studies that investigate various aspects associated with the economics of charitable giving. The issue also includes a fitting tribute to one of the earliest experimenters to depart from traditional lab methods, Peter Bohm, who curiously has not received deep credit or broad acclaim. Hopefully this issue will begin to rectify this oversight.

Peter Bohm (1935-2005) was the father of modern field experiments. He clearly understood and stated the differences between laboratory experiments and experiments with field counterparts. His research was a clear precursor to the methodology that is now becoming widely accepted as complementary to laboratory experiments.

In this paper we study the effect of downward social information in contribution decisions to fund public goods. We describe the results of a field experiment run in conjunction with the fundraising campaigns of a public radio station. Renewing members are presented with social information (information about another donor's contribution) which is either above or below their previous (last year's) contribution. We find that respondents change their contribution in the direction of the social information; increasing their contribution when the social information is above their previous contribution, and decreasing their contribution when the social information is below. We hypothesize about the psychological motivations that may cause the results and test these hypotheses by comparing the relative size of the upward and downward shifts. These results improve our understanding of cooperation in public good provision and suggest differential costs and benefits to fundraisers in providing social information.

We report the results of a field experiment conducted in conjunction with a mailed fundraising campaign of a nonprofit organization. The experiment is designed to compare the response of donors to subsidies in the form of matching amounts or rebated amounts. Matching subsidies are used by many corporations as an employee benefit; the US federal tax system encourages giving using a rebate subsidy by making donations tax deductible. The design includes a control group and two levels of subsidy of each type. Our main result is that matching subsidies result in larger total donations to charities than rebate subsidies, a result that is qualitatively similar to the lab findings. The estimated price elasticities for the matching subsidy are very similar to (and insignificantly different from) the lab experiments, while rebate subsidies lead to lower contributions in the field than in the lab. Since rebates in the field involve substantial lags and additional complications as compared with the “instant rebates” of the lab, this latter difference is not unexpected. The matching results are an important step in validating lab estimates of responsiveness to subsidies of charitable giving.

This study designs a natural field experiment linked to a controlled laboratory experiment to examine the effectiveness of matching gifts and challenge gifts, two popular strategies used to secure a portion of the $200 billion annually given to charities. We find evidence that challenge gifts positively influence contributions in the field, but matching gifts do not. Methodologically, we find important similarities and dissimilarities between behavior in the lab and the field. Overall, our results have clear implications for fundraisers and provide avenues for future empirical and theoretical work on charitable giving.

Laboratory experiments are an important methodology in economics, especially in the field of behavioral economics. However, it is still debated to what extent results from laboratory experiments are informative about behavior in field settings. One highly important question about the external validity of experiments is whether the same individuals act in experiments as they would in the field. This paper presents evidence on how individuals behave in donation experiments and how the same individuals behave in a naturally occurring decision situation on charitable giving. While we find evidence that pro-social behavior is more accentuated in the lab, the data show that pro-social behavior in experiments is correlated with behavior in the field.

We conduct a representative dictator game in which students and random members of the community choose both what charity to support and how much to donate to the charity. We find systematic differences between the choices of students and community members. Community members are much more likely to write in their own charity, community members donate significantly more ($17), on average, and community members are much more likely (32%) to donate the entire $100 endowment. Based on this evidence, it does not appear that student behavior is very representative in the context of the charitable donations and the dictator game.

We investigated the importance of the social context for people's voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and information provided about the contributions of others influence subject contributions in the hypothesized direction. We found a substantial hypothetical bias with regard to the amount contributed. However, the influence of the social contexts is about the same when the subjects make actual monetary contributions as when they state their hypothetical contributions. Our results have important implications for validity testing of stated preference methods: a comparison between hypothetical and actual behavior should be done for a given social context.