Digital technologies can expand access to health services to underserved populations. This paper leverages mobile network expansion and survey data spanning two decades to study the impact of access to mobile phones on infant mortality in Africa. Using plausibly exogenous variations in lightning...

This paper investigates how people's happiness depends on their current activities and on time. We conducted an hourly web survey, in which 70 students reported their happiness every hour on one day every month from December 2006 to February 2008. This method is an extension of the experience...