At the time, the president proposed tying federal aid to the rating system to incentivize schools to help their students graduate with an affordable education.President Obama and first lady Michelle Obama will host an event on college affordability next Thursday at the White House. While White House press secretary Jay Carney did not provide details about the event, it is likely a make-up of a summit with college presidents and members of the private sector that had been planned for early last month. The White House was forced to scrap that event after the death of South African President Nelson...