Hope Street Group's Amanda Levinson and Dmitri Mehlhorn write about opportunity and redemption in the San Diego Union-Tribune.

While FEMA's sense of urgency is appropriate, this solution is short-sighted – and, indeed, ignores the experiences of a half-century of experimentation with public housing. Originally, public housing "projects" were designed to be inexpensive and transitional housing for poor families. In practice, however, these projects turned out to be anything but cheap or temporary, with residents instead mired for generations in dangerous, desperate living conditions with exceptionally high rates of unemployment and crime.

By engaging in large-scale public engineering without forethought, we risk making the same expensive mistake today. These "temporary" trailer parks will likely prove permanent, and the hundreds of thousands of mobile homes will become our newest ghettos – isolated from the jobs, transportation, education, and other social services they will need to get back on their feet.

We can do better. American cities today have millions of vacant rental units. According to the Census Bureau, the nation currently has nearly 3.7 million vacant rental units. We can make at least some of those units available to the displaced families of the Gulf Coast if we take several steps.