Researchers frequently deliver treatments through messages, as in many audit and get-out-the-vote (GOTV) experiments. These message-based experiments often hinge on intermediary variables—actions subjects must take to actually receive the treatment or control embedded in a message. Whether subjects open the message is a crucial intermediary step, which can serve as a condition for estimating downstream treatment effects or as an outcome of interest in its own right. Yet opens are often measured with error, most notably when some openers are misclassified as non-openers in email-based studies. We characterize the resulting bias, derive interpretable bounds on effects for well-defined subgroups, and provide sensitivity analyses for mismeasurement, thereby offering practical guidance for message-based experiments conducted through email and other communication technologies.

Does an MP's localness affect their behaviour towards constituents? Existing research has shown biases in MPs' responsiveness to citizens based on citizens' sociodemographic and political traits and voters’ tendency to prefer ‘local’ MPs. Yet, we know little about whether MPs' localness affects their responsiveness to constituents. MPs' localness may influence their behaviour for strategic reasons and/or because of homophily. To explore this relationship, we conducted a field experiment in the United Kingdom where we asked legislators about their policy priorities regarding the COVID-19 pandemic. We found that local MPs do not differentiate in their responsiveness to constituents. However, non-local MPs are motivated by party affiliation and gender in their responsiveness to constituents, with ethnicity and class playing insignificant roles. Non-local MPs respond more to co-partisans than non-partisans and women non-local MPs are more responsive to women constituents. This experiment underscores the impact of (non-)localness on MPs' interactions with constituents.

Federal systems can also provide citizens with multiple avenues to obtain service representation. In shared issue areas, citizens are officially represented by two sets of politicians. When politicians are willing to cross jurisdictional boundaries, citizens might also obtain help or information from more than one set of politicians, even in areas of exclusive jurisdiction. We report an experiment designed to examine responses to requests for assistance in different issue areas. Our sample includes 202 Canadian politicians, each of whom received two requests for assistance from fictional constituents. We show that federal arrangements can enhance service representation. On average, politicians are as helpful on issues of shared jurisdiction as issues of exclusive jurisdiction. They are less helpful for issues outside of their jurisdiction. These results suggest that federal arrangements can work to provide citizens with multiple access points to their representative, even in areas that fall outside their representatives’ jurisdictional purviews.