''A manual for the 21st-century citizen... accessible, refreshingly critical, relevant and urgent'' - Financial Times ''Fascinating and deeply disturbing'' - Yuval Noah Harari, Guardian Books of the Year In this New York Times bestseller, Cathy O''Neil, one of the first champions of algorithmic accountability, sounds an alarm on the mathematical models that pervade modern life -- and threaten to rip apart our social fabric.We live in the age of the algorithmIncreasingly, the decisions that affect our lives - where we go to school, whether we get a loan, how much we pay for insurance - are being made not by humans, but by mathematical models. In theory, this should lead to greater fairness: everyone is judged according to the same rules, and bias is eliminated.And yet, as Cathy O''Neil reveals in this urgent and necessary book, the opposite is true. The models being used today are opaque, unregulated, and incontestable, even when they''re wrong. Most troubling, they reinforce discrimina