"Lepore is a brilliant and prolific historian with an eye for unusual and revealing stories, and this one is a remarkable saga, sometimes comical, sometimes ominous: a “shadow history of the 1960s,” as she writes.... Lepore finds in it a plausible untold origin story for our current panopticon: a world of constant surveillance, if not by the state then by megacorporations that make vast fortunes by predicting and manipulating our behavior—including, most insidiously, our behavior as voters.... It didn’t have to be this way. That is Lepore’s final message: history is not inevitable."

"Lepore is a brilliant and prolific historian with an eye for unusual and revealing stories, and this one is a remarkable saga, sometimes comical, sometimes ominous: a “shadow history of the 1960s,” as she writes.... Lepore finds in it a plausible untold origin story for our current panopticon: a world of constant surveillance, if not by the state then by megacorporations that make vast fortunes by predicting and manipulating our behavior—including, most insidiously, our behavior as voters.... It didn’t have to be this way. That is Lepore’s final message: history is not inevitable."

"Fascinating.... Over the last decade, Lepore, a Harvard history professor and New Yorker staff writer, has repeatedly shown herself to be an uncommonly astute and insightful interpreter of American history, and one of her many strengths is the moral clarity that infuses her writing.... [with] a nimble fluency that can be exhilarating."

"Timely.... Lepore weaves her narrative across continents and through time with engaging, conversational prose. Her characters' personalities, families, affairs, fights and constant gossiping come alive, thanks to extensive troves of family papers and interviews with those closest to them."

"[A] rich account. . . . Lepore’s exceptional skill as storyteller and her sharp eye for seemingly quotidian details and small coincidences lend the Simulmatics world an intimate—and at times deliciously gossipy—feeling. . . . As Lepore notes, after the 1960 Kennedy election, the idea that politicians might use advertising, psychological tricks, or even new technology in order to sway elections in their favor was still shocking to the public. But 60 years later, it’s such an accepted part of American political life that it takes a historian to excavate the moment in time where such notions began to cohere."

"A beautifully written and intellectually rigorous account of the origins of the science of predictive analytics and behavioral data science in the cold war era."

"In If Then, Lepore skillfully argues that their use of technology brought us to this current political climate."

"[Lepore] pulls no punches in criticizing the folly of trying to understand human behavior via algorithm, and the corrosive consequences of trying to hack democracy. The result is . . . a perceptive work of historically informed dissent."

"A staff writer for the New Yorker and Harvard professor, Lepore knows how to spin out a winning historical study. Here, she dives deep into matters that have seldom attracted scholarly attention. . . As Lepore convincingly demonstrates, the work of Simulmatics paved the way for later manipulators of psychology and public opinion such as Facebook. . . . A fascinating, expertly guided exploration of a little-known corner of the recent past."

"A person can’t help but feel inspired by the riveting intelligence and joyful curiosity of Jill Lepore. Knowing that there is a mind like hers in the world is a hope-inducing thing."

"Jill Lepore reveals how this forgotten company invented the data-weapons of the future. If Then is simultaneously gripping and absolutely terrifying."

"Everything Jill Lepore writes is distinguished by intelligence, eloquence, and fresh insight. If Then is that, and even more: It’s absolutely fascinating, excavating a piece of little-known American corporate history that reveals a huge amount about the way we live today and the companies that define the modern era."

"Hilarious, scathing and sobering – what you might get if you crossed Mad Men with Theranos."

"In another fast-paced narrative, Jill Lepore brilliantly uncovers the history of the Simulmatics Corporation, which launched the volatile mix of computing, politics, and personal behavior that now divides our nation, feeds on private information, and weakens the strength of our democratic institutions."

"In this page-turning, eye-opening history, Jill Lepore reveals the Cold War roots of the tech-saturated present, in a thrilling tale that moves from the campaigns of Eisenhower and Kennedy to ivied think tanks, Madison Avenue ad firms, and the hamlets of Vietnam. Told with verve, grace, and humanity, If Then is an essential, sobering story for understanding our times."

"Lepore writes history like a poet. In If Then she yet again binds lyrical storytelling to meticulous archival research to tell a gigantic story from our past."

"Data science, Jill Lepore reminds us in this brilliant book, has a past, and she tells it through the engrossing story of Simulmatics, the tiny, long-forgotten company that helped invent our data-obsessed world, in which prediction is seemingly the only knowledge that matters. A captivating, deeply incisive work."

Jill Lepore is the David Kemper ’41 Professor of American History at Harvard University and a staff writer at The New Yorker. A two-time Pulitzer Prize finalist, her many books include the international bestseller These Truths and If Then, which was longlisted for the National Book Award.