In tough times, the poor get poorer. That's a major message of a UCLA study of California schools during the downturn. "For every dollar a low-income school raises," the study found, "a high-income school raises $20."

The study should be treated with some caution. It focuses on only one state, and the sample of 277 schools is a bit small. Still, it offers a stark reminder that low-income schools can fall even farther behind in lean times.