We conducted a large-scale online experiment to examine whether climate change messaging can induce emotions and motivate pro-environmental action. We study how exposure to explicit positive (‘warm glow’) and negative (‘cold prickle’) emotional appeals as well as a traditional social norm communication affects pro-environmental action. We find that a simple call to take action to mitigate climate change is at least as affective as social norm message framing and emotional appeals. Our results highlight the difficulty of designing messaging interventions that effectively harness emotional incentives to promote pro-environmental action. Messages that explicitly emphasise the personal emotional benefits of contributing to environmental causes or the adverse emotional effects of not doing so seem to fall short of motivating pro-environmental effort. Our findings underscore the need for caution when incorporating emotive appeals into policy interventions.

We use an online experiment to study the relative effect on voter behavior of a candidate’s voice pitch and policy stance. We demonstrate a strong voice-pitch bias: between candidates who are identical in every other aspect, voters are more likely to choose the one with the lower voice-pitch, and more so in elections between men than women candidates. We then introduce a novel phenomenon: persistence of voice-pitch bias is the amount of policy difference needed to compensate for voice-pitch bias. While persistence is also gender-dependent, the effect is now reversed: voice-pitch bias is more persistent in elections between women than men candidates. As a possible mechanism, we show that voters perceive candidates with lower voice-pitch as more competent and trustworthy.

Increasingly, experimental research is being conducted on the Internet in addition to the laboratory. Online experiments are more convenient for subjects and researchers, but we know little about how the choice of study location affects data quality. To investigate whether respondent behavior differs across study location, we randomly assign subjects to participate in a study in a laboratory or in an online setting. Contrary to our expectations, we find few differences between participants in terms of the level of attention and socially desirable responding. However, we find significant differences in two areas: the degree of self-reported distractions while completing the questionnaire and the tendency to consult outside sources for answers to political knowledge questions. We conclude that when the greater convenience (and higher response rates) of online experiments outweighs these disadvantages, Internet administration of randomized experiments represent an alternative to laboratory administration.