My gratitude goes as well to the other data scientists I pestered and to the institutions that collect and maintain their data: Karlyn Bowman, Daniel Cox (PRRI), Tamar Epner (Social Progress Index), Christopher Fariss, Chelsea Follett (HumanProgress), Andrew Gelman, Yair Ghitza, April Ingram (Science Heroes), Jill Janocha (Bureau of Labor Statistics), Gayle Kelch (US Fire Administration/FEMA), Alaina Kolosh (National Safety Council), Kalev Leetaru (Global Database of Events, Language, and Tone), Monty Marshall (Polity Project), Bruce Meyer, Branko Milanovic (World Bank), Robert Muggah (Homicide Monitor), Pippa Norris (World Values Survey), Thomas Olshanski (US Fire Administration/FEMA), Amy Pearce (Science Heroes), Mark Perry, Therese Pettersson (Uppsala Conflict Data Program), Leandro Prados de la Escosura, Stephen Radelet, Auke Rijpma (OECD Clio Infra), Hannah Ritchie (Our World in Data), Seth Stephens-Davidowitz (Google Trends), James X. Sullivan, Sam Taub (Uppsala Conflict Data Program), Kyla Thomas, Jennifer Truman (Bureau of Justice Statistics), Jean Twenge, Bas van Leeuwen (OECD Clio Infra), Carlos Vilalta, Christian Welzel (World Values Survey), Justin Wolfers, and Billy Woodward (Science Heroes). David Deutsch, Rebecca Newberger Goldstein, Kevin Kelly, John Mueller, Roslyn Pinker, Max Roser, and Bruce Schneier read a draft of the entire manuscript and offered invaluable advice.