Books of The Times: ‘Big Data,’ by Viktor Mayer-Schönberger and Kenneth Cukier

Does what? Uses “big data” analysis of the swelling flood of data that is being generated and stored about virtually every aspect of our lives to identify patterns of behavior and make correlations and predictive assessments.

Amazon uses customer data to give us recommendations based on our previous purchases. Google uses our search data and other information it collects to sell ads and to fuel a host of other services and products.

The National Security Agency, a news article in The Guardian revealed last week, is collecting the phone records of millions of American customers of Verizon — “indiscriminately and in bulk” and “regardless of whether they are suspected of any wrongdoing” — under a secret court order. Under another surveillance program called Prism, The Guardian and The Washington Post reported, the agency has been collecting data from e-mails, audio and video chats, photos, documents and logins, from leading Internet companies like Microsoft, Yahoo, Google, Facebook and Apple, to track foreign targets.

Why spread such a huge net in search of a handful of terrorist suspects? Why vacuum up data so indiscriminately? “If you’re looking for a needle in the haystack, you need a haystack,” Jeremy Bash, chief of staff to Leon E. Panetta, the former director of the Central Intelligence Agency and defense secretary, said on Friday.

In “Big Data,” their illuminating and very timely book, Viktor Mayer-Schönberger, a professor of Internet governance and regulation at the Oxford Internet Institute at Oxford University, and Kenneth Cukier, the data editor for The Economist, argue that the nature of surveillance has changed.

“In the spirit of Google or Facebook,” they write, “the new thinking is that people are the sum of their social relationships, online interactions and connections with content. In order to fully investigate an individual, analysts need to look at the widest possible penumbra of data that surrounds the person — not just whom they know, but whom those people know too, and so on.”

Mr. Cukier and Mr. Mayer-Schönberger argue that big data analytics are revolutionizing the way we see and process the world — they even compare its consequences to those of the Gutenberg printing press. And in this volume they give readers a fascinating — and sometimes alarming — survey of big data’s growing effect on just about everything: business, government, science and medicine, privacy and even on the way we think. Notions of causality, they say, will increasingly give way to correlation as we try to make sense of patterns.

Data is growing incredibly fast — by one account, it is more than doubling every two years — and the authors of this book argue that as storage costs plummet and algorithms improve, data-crunching techniques, once available only to spy agencies, research labs and gigantic companies, are becoming increasingly democratized.

Big data has given birth to an array of new companies and has helped existing companies boost customer service and find new synergies. Before a hurricane, Walmart learned, sales of Pop-Tarts increased, along with sales of flashlights, and so stores began stocking boxes of Pop-Tarts next to the hurricane supplies “to make life easier for customers” while boosting sales. UPS, the authors report, has fitted its trucks with sensors and GPS so that it can monitor employees, optimize route itineraries and know when to perform preventive vehicle maintenance.

Baseball teams like Billy Beane’s Oakland A’s (immortalized in Michael Lewis’s best-seller “Moneyball”) have embraced new number-crunching approaches to scouting players with remarkable success. The 2012 Obama campaign used sophisticated data analysis to build a formidable political machine for identifying supporters and getting out the vote. And New York City has used data analytics to find new efficiencies in everything from disaster response, to identifying stores selling bootleg cigarettes, to steering overburdened housing inspectors directly to buildings most in need of their attention. In the years to come, Mr. Mayer-Schönberger and Mr. Cukier contend, big data will increasingly become “part of the solution to pressing global problems like addressing climate change, eradicating disease and fostering good governance and economic development.”

There is, of course, a dark side to big data, and the authors provide an astute analysis of the dangers they foresee. Privacy has become much more difficult to protect, especially with old strategies — “individual notice and consent, opting out and anonymization” — losing effectiveness or becoming completely beside the point.

“The ability to capture personal data is often built deep into the tools we use every day, from Web sites to smartphone apps,” the authors write. And given the myriad ways data can be reused, repurposed and sold to other companies, it’s often impossible for users to give informed consent to “innovative secondary uses” that haven’t even been imagined when the data was first collected.