The diverse coalition of delegates who attended the Democratic National Convention last week may not have realized they were visiting one of the most segregated cities in the U.S. But even as a child growing up in a gentrifying, white enclave of West Philadelphia, Jonathan Tannen knew that people with his skin color rarely crossed 49th Street. It was the invisible line that separated his neighborhood from majority-black areas in the 1980s.
Two decades later, Tannen would spend six years at Princeton University working on a dissertation to quantify what he’d long suspected: that the invisible lines of segregation can be as real and hard as the bricks of any rowhome.
“I wanted to see if I could measure lines between regions with very different racial characteristics,” he says.
Through his research he used a computer program to detect racial borders, like 49th Street, in the 100 largest U.S. cities. But along the way, he found something else that surprised him: As more suburban whites moved back to urban areas, old racial boundaries were moving, and spreading outward. But the neighborhoods themselves weren’t desegregating.
In fact, they were resegregating.
“You’re not seeing this historically black area becoming five percent white over ten years and then ten percent white. Instead, they went from almost 100 percent black to almost 100 percent white over ten years,” he says. “Philadelphia overall is becoming less white. But there are pockets of predominately white regions that are expanding. And the blocks along those boundaries are flipping very quickly, from a racial standpoint.”
[For more of this story, written by Ryan Briggs, go to http://www.citylab.com/housing...philadelphia/493313/]