There is no better way to improve the lives of billions of people around the world than to improve the way cities work. For the first time in human history, the majority of the world's people live in cities. By 2050, 75 percent will. As more and more people move to cities, more and more of the world's challenges—and solutions—will be concentrated there, too.

The rise of cities coincides with a technological revolution that is empowering local leaders to find innovative new ways to better serve the public. At the center of that revolution is our growing ability to use data to improve the services that government provides. Governments have long been in the business of keeping records, and increasingly they are using those records—billions of data points—to improve everything from emergency response to education to transportation.

I have a rule of thumb: if you can't measure it, you can't manage it. And I brought that approach with me from the private sector to New York's city hall. Our administration looked for ways to use data—and to collect more data—to help us better serve New Yorkers.

In 2003, we launched 311, a nonemergency government information and services hotline available to New Yorkers twenty-four hours a day, seven days a week. Not only did 311 make it easier for New Yorkers to get information from the city—and to file complaints—it also gave city government more information on what New Yorkers were concerned about and helped us keep track of how well we were doing at addressing those concerns.

We also created data systems to measure agency performance and hold ourselves accountable for results. And we took a page from the private sector and brought predictive analytics to local government, using city data to help foresee the challenges of the future—and took action to address them today.

Harnessing and understanding data helped us decide how to allocate resources more efficiently and effectively, which allowed us to improve the delivery of services—from protecting children and fighting crime to repairing potholes and inspecting buildings—while also saving taxpayer money.

Cities and mayors everywhere are recognizing the powerful role data can play in bringing more transparency, accountability, and efficiency to government—and Bloomberg Philanthropies is helping to support this work. For instance, in 2013 the city of Chicago was one of five winners of the Mayors Challenge, an ideas competition for cities, for its groundbreaking idea to use data to help city government prevent problems before they develop. Chicago is quickly setting a new standard, which other cities will surely follow.

Across so much of the work we do with cities—from our innovation delivery program helping New Orleans reduce gun violence to our work with cities around the world to reduce carbon emissions—we see data enabling new and creative approaches. Of course, driving change in cities requires more than just data. It also requires strong managers and creative problem solvers—and Stephen Goldsmith is both. I was lucky to have him join me at city hall as a deputy mayor during my third term in office, and he helped us take our efforts to improve city services to new levels.

In the chapters that follow, Goldsmith and his talented coauthor, Susan Crawford, demonstrate how local leaders are changing the way governments work. Through case studies from New York City, Boston, and Chicago, they explain how data mining, empowered public servants, mobile apps, wireless devices, technically supported citizens, and social media can produce a dramatically more responsive city. And they show how these tools can be used by both elected and community leaders to drive change and improve a neighborhood's quality of life.

Cities will increasingly define the future, in America and around the world. And cities that capitalize on the technology revolution will lead the way. This book helps point the way forward.

June 2014

Michael Bloomberg
Former mayor of New York City