Can gathering happiness data help countries evaluate the success of public policies? For our regular segment “Is This Bulls—t,” we examine the value of happiness studies with Maria Konnikova of The New Yorker. Also, Arab studies professor Justin Stearns explains how the Muslim world interprets extremist calls for a return to the caliphate. For the Spiel, Mike remembers Robin Williams in light of our recent report on comedy and mental health. Get The Gist by email as soon as it’s available: slate.com/GistEmail Subscribe to the podcast in iTunes: itunes.apple.com/us/podcast/slate…id873667927?mt=2