The University of Michigan on Friday promoted news coverage of an open letter  on college costs by Mary Sue Coleman, president of the institution, to President Obama. "Higher education is a public good currently lacking public support. There is no stronger trigger for rising costs at public universities and colleges than declining state support," Coleman wrote. In the letter, she praised Obama for recently gathering a small group of college presidents  to talk about college costs. But in offering this public advice to Obama, Coleman didn't note that she was one of the presidents invited to the White House, but sent her regrets. A spokeswoman said that Coleman's "schedule wouldn't permit" her to join the White House meeting.