Detroit’s bankruptcy and the problems facing its pension funds offer two important lessons to other communities. One is that state and local governments need to do a much better job managing retirement funds. The other is that they should not pre-emptively reduce hard-earned benefits at the first sign of trouble. Several state and local pension systems around the country are under serious stress. Not surprisingly the hardest hit retirement funds are in places devastated by global economic forces like Detroit, as well as inland cities in California like Stockton, which was battered by the real estate collapse and has also...