DALLAS, TX (Metro Source) - Michigan's economy slowed slightly in May, with the Japanese earthquake and tsunami earlier this year blamed for disrupting the auto industry supply chain. Comerica Bank's Michigan Economic Activity Index fell by one point in May but remains higher than a year ago. Comerica economists at the company headquarters in Dallas expect this state's economy to start to pick up again in the coming months now that auto production in Japan has started to get back to normal.