The opioid epidemic is a major public health problem that affects millions of people around the world. This paper addresses one challenge identified on the demand side of the epidemic: A large proportion of patients prescribed opioids lose track of their unused pills or save them for future use....

This article argues that public opinion regarding the legitimacy of income differences is influenced by actual income inequality. When income differences are (perceived to be) high, the public thinks of larger income inequality as legitimate. The phenomenon is explained by the system...

Decisions, both moral and mundane, about saving individuals or resources at risk are often influenced not only by numbers saved and lost, but also by proportions of groups saved and lost. Consider choosing between a program that saves 60 of 240 lives at risk and one that saves 50 of 100. The...

To encourage health insurance uptake, marketers and policymakers have focused on consumers’ economic self-interest, attempting to show that insurance is a good deal or to sweeten the deal, with subsidies or penalties. Still, some consumers see insurance as a bad deal, either because they...

We describe what is a pre-analysis plan (PAP) and why you should use one. We emphasize the potential political uses of PAPs and, in particular, how the PAP is in this respect a uniquely powerful tool for increasing the likelihood that evidence informs policy-making

Widespread acceptance of COVID-19 vaccines is crucial for achieving sufficient immunization coverage to end the global pandemic, yet few studies have investigated COVID-19 vaccination attitudes in lower-income countries, where large-scale vaccination is just beginning. We analyze COVID-19...

This issue brief presents baseline findings from the impact evaluation and the case study before the installation of a new electricity cable connecting Unguja Island in Zanzibar to the electricity grid of mainland Tanzania. Information for the baseline analysis comes from electricity data...

This report describes the data, design, and methodology for an impact evaluation of the Millennium Challenge Corporation's Zanzibar Cable Activity, which involves laying a new submarine cable to provide a more reliable source of electricity to Unguja Island to increase economic growth, reduce...

When communicating numeric estimates with policymakers, journalists, or the general public, experts must choose between using numbers or natural language. We run two experiments to study whether experts strategically use language to communicate numeric estimates in order to persuade receivers....