Two preliminary studies suggest that the Bloomberg administration's controversial report cards for schools may be useful in getting those struggling schools to succeed. The Post reports that students in previously failing schools are now doing better on their state tests (which is a big component of the school report cards). Columbia professor Jonah Rockoff, who worked on one study, explained, "One of the big benefits of this accountability system is that it lights a fire under the schools that are lagging behind." Another former Department of Education official credited mayoral control of the schools, "The old Board of Education was unwilling to hold schools accountable for performance. They were more interested in making excuses." However, there are still critics: NYU professor Diane Ravitch, who recently disputed Bloomberg's claims to school success in a Times Op-Ed, says city "look[s] at closing schools joyfully" so charter schools can be put in. Last fall, when school report cards were released, critics also pointed out how school grades focus too much on year-to-year improvements versus proficiency.