A University of Chicago study found that Chicago school children who were forced to repeat third or sixth grade didn't show the expected academic gains and researchers found that eighth graders who were held back were much more likely to later drop out of school.
The U of C researchers say the Chicago public school policy of flunking kids should be scrapped. They say holding students back a grade should be a last resort.
But Chicago schools CEO Arne Duncan says the city's decision to fail under-performing students has improved test scores and lowered the dropout rate.
Between 7,000 and 10,000 students have been held back a grade in Chicago's public schools in recent years.