Chicago researchers assess the city's commitment to fail kids who fail tests as better politics than policy: Retention didn't help third-graders; it hurt sixth-graders, and it made eighth-graders far more likely to drop out, the studies of the early years of the policy found. Kids who repeated two grades were in high peril of dropping out by age 19, with 78 percent doing so, one study found. In addition, researchers said, retained kids were three to six times more likely to wind up in special education -- where they struggled more -- compared to similar low-scoring kids promoted during the same time frame.