Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy

by Cathy O'Neil

On a summer day in 2013, I took the subway to the southern tip of Manhattan and walked to a large administrative building across from New York’s City Hall. I was interested in building mathematical models to help society—the opposite of WMDs. So I’d signed on as an unpaid intern in a data analysis group within the city’s Housing and Human Services Departments. The number of homeless people in the city had grown to sixty-four thousand, including twenty-two thousand children. My job was to help create a model that would predict how long a homeless family would stay in the shelter system and to pair each family with the appropriate services. The idea was to give people what they needed to take care of themselves and their families and to find a permanent home. My job, in many ways, was to help come up with a recidivism model. Much like the analysts building the LSI–R model, I was interested in the forces that pushed people back to shelters and also those that led them to stable housing. Unlike the sentencing WMD, though, our small group was concentrating on using these findings to help the victims and to reduce homelessness and despair. The goal was to create a model for the common good.