It is hard to believe that we have been at this for four years, but our term as editors is coming to a close. During this time, JEPS has gone from being little more than an idea in a few people's minds to a full fledged journal with robust submissions, excellent reviewers, and valuable published research from a wide range of scholars featuring all different types of experimental analyses employed in the study of politics. We are extremely excited by what JEPS has become, and we hope you share our enthusiasm!

Survey experiments have become a central methodology across the social sciences. Researchers can combine experiments’ causal power with the generalizability of population-based samples. Yet, due to the expense of population-based samples, much research relies on convenience samples (e.g. students, online opt-in samples). The emergence of affordable, but non-representative online samples has reinvigorated debates about the external validity of experiments. We conduct two studies of how experimental treatment effects obtained from convenience samples compare to effects produced by population samples. In Study 1, we compare effect estimates from four different types of convenience samples and a population-based sample. In Study 2, we analyze treatment effects obtained from 20 experiments implemented on a population-based sample and Amazon's Mechanical Turk (MTurk). The results reveal considerable similarity between many treatment effects obtained from convenience and nationally representative population-based samples. While the results thus bolster confidence in the utility of convenience samples, we conclude with guidance for the use of a multitude of samples for advancing scientific knowledge.

We conduct a laboratory experiment to study the incentives of a privileged group (the “yellows”) to share political power with another group (the “blues”). The yellows collectively choose the voting rule for a general election: a simple-majority rule that favors them, or a proportional rule. In two treatments, the blues can use a costly punishment option. We find that the yellows share power voluntarily only to a small extent, but they are more inclined to do so under the threat of punishment, despite the fact that punishments are not sub-game perfect. The blue group conditions punishments both on the voting rule and the electoral outcome.

A large literature argues that the committee assignment process plays an important role in shaping legislative politics because some committees provide legislators with substantial benefits. However, evaluating the degree to which legislators benefit from winning their preferred assignments has been challenging with existing data. This paper sheds light on the benefits legislators accrue from winning their preferred committee assignments by exploiting rules in Arkansas’ state legislature, where legislators select their own committee assignments in a randomized order. The natural experiment indicates that legislators reap at most limited rewards from winning their preferred assignments. These results potentially raise questions about the robustness of widely held assumptions in literatures on party discipline and legislative organization.

Branding of foreign aid may undermine government legitimacy in developing countries when citizens see social services being provided by external actors. We run a survey experiment on a sample of Indian respondents. All subjects learn about an HIV/AIDS program; treated subjects learn that it was foreign-funded. We find null results that, along with existing results in the literature obtained from observational data, call into question the view that foreign-funded service delivery interferes with the development of a fiscal contract between the state and its citizens.

Recent research has uncovered a dynamic role for emotion in political decision-making. Anger in particular has increased in importance as scholars uncover its role in motivating participation and partisanship. One method for examining these effects is to use an induction to invoke an emotion, though such techniques are often limited to the laboratory. We discuss pertinent psychological research on induction, test several methods, and make practical recommendations for political science survey research. Using a unique research design which varies the way anger is invoked, we first find significant effects using a scenario induction. We replicate these findings with an adult sample and extend the results to political inductions. We are able to offer practical advice to scholars interested in replicating the effects of angry campaign ads or better understanding the effects of anger arousal on political behavior.

We report the results of a field experiment conducted in New York City during the 2013 election cycle, examining the impact of nonpartisan messages on donations from small contributors. Using information from voter registration and campaign finance records, we built a forecasting model to identify voters with an above-average probability of donating. A random sample of these voters received one of four messages asking them to donate to a candidate of their choice. Half of these treatments reminded voters that New York City's campaign finance program matches small donations with public funds. Candidates’ financial disclosures to the city's Campaign Finance Board reveal that only the message mentioning policy (in generic terms) increased donations. Surprisingly, reminding voters that matching funds multiplied the value of their contribution had no effect. Our experiment sheds light on the motivations of donors and represents the first attempt to assess nonpartisan appeals to contribute.

In this essay, we closely examine three aspects of the Reporting Guidelines for this journal, as described by Gerber et al. (2014, Journal of Experimental Political Science 1(1): 81–98) in the inaugural issue of the Journal of Experimental Political Science. These include manipulation checks and when the reporting of response rates is appropriate. The third, most critical, issue concerns the committee's recommendations for detecting errors in randomization. This is an area where there is evidence of widespread confusion about experimental methods throughout our major journals. Given that a goal of the Journal of Experimental Political Science is promoting best practices and a better understanding of experimental methods across the discipline, we recommend changes to the Standards that will allow the journal to play a leading role in correcting these misunderstandings.