For many urban planners and new urbanists, the U.S. census numbers released in 2010 were demoralizing.

They had anticipated that Americans, after decades of fleeing to suburbs, would reverse that trend in the 2000s and begin returning to rebuilt cities. Instead, suburban growth increased. According to New Geography, 91 percent of growth over the decade occurred in suburbs, an increase from the 1990-2000 timespan in which 85 percent occurred in suburbs.

But there is one kernel of optimism in the numbers for city lovers: some urban cores are growing.

Writing for New Geography last week, Aaron M. Renn says in some cities “we see that over the 2000s out-migration from the core to the suburban counties was relatively flat or even declined late in the decade as general mobility declined in the Great Recession. In contrast, migration from the suburban counties to the core stayed flat or actually increased.”

He presents evidence of core growth in St. Louis, New York, Philadelphia, San Francisco and Washington D.C. While a fledgling revitalization in Detroit has occurred too recently to show up in census numbers to make apples-to-apples comparisons to the cities above, there’s anecdotal evidence of a similar small-scale influx.

Although Detroit’s overall population plummeted by 25 percent between 2000 and 2010, according to the census figures, the number of college-educated residents under age 35 increased downtown by 59 percent.

This past July, five of the city’s key employers announced a program that provides employees with cash incentives to move downtown, and more cash to maintain their homes once they relocate. More than 16,000 employees of Blue Cross Blue Shield of Michigan, DTE Energy, Compuware, Quicken Loans and Strategic Staffing Solutions are eligible.

There’s a key advantage, Renn writes, Detroit holds over other Midwestern cities that are trying to bolster their cores even as other residents leave.

“It’s possible to do things there,” he says. “In Detroit, the incapacity of the government is actually an advantage in many cases.” He says much of Chicago’s South Side shares characteristics of Detroit, but strict enforcement of arcane codes would stifle creativity and entrepreneurship. Likewise in Indianapolis, historic district restrictions force fixer-uppers to “run a costly and grueling gauntlet of variances, permits, hearings, etc.”

That doesn’t happen in Detroit.

“In Detroit, if you want to do something, you just go do it,” Renn writes. “It is certainly easier to make things happen there than in most places.”