Empty Schools Declining school-age populations and enrollment are contributing to increased budget pressures and credit downgrades for Michigan public schools, Moody's Investors Service said Tuesday. (File photo) LANSING -- The number of Michigan public school districts seeing their credit ratings downgraded has exploded in 2013, with a 64 percent increase in the number of districts compared to last year, Moody's Investors Service said Tuesday. A total of 53 districts, or nearly one-quarter of the districts Moody's rates in Michigan, have been downgraded at least once since January, analysts with the company said in a report, and some districts have been downgraded more than once. The decline in ratings is attributed in the report to increased retirement system costs, a declining student population, declining enrollment compared to charter schools and an increase in the number of charter schools operating in the state.