Funds from this grant support three different large-scale and randomized field experiments, devised by economists Matthew Gentzkow at Stanford and Hunter Allcott at New York University, that aim to help us better understand the various ways social media and smartphones impact our lives. In the first, Gentzkow and Allcott study the welfare implications of Facebook usage by measuring the impact of cutting off access to that platform. In the second experiment, the team studies how limiting smartphone access to social media and other apps affects the welfare of college students. The third experiment concerns the demand for “fake news” and investigates what happens to consumer behavior when incentives to find accurate information increase. Grant funds support the fielding and analysis of all three experiments as well as documentation of methods to enable easy replication by other scholars.