Randomised test are carried out on us every day: by supermarkets, search engines, online dating sites, political parties and direct marketers. but how do these tests work? Are there any ethical issues? And what do they reveal about our choices?

In Randomistas, Andrew Leigh tells the stories of radical researchers who overturned conventional wisdom in medicine, politics, business, law enforcement and more. From finding the cure to scurvy to discovering what policies really improve literacy rates, randomistas have shaped life as we know it - but they often had to fight to conduct their trials and have their findings implemented.