When I first read Education Gadfly's post critiquing the Quality Counts 2008 report, I was struck by his reference to teachers only working 9 months as I always had to work longer. In looking over Missouri's data, however, I can see the disconnect.
While Mo. teachers ave. 181.49 contract days, St. Louis teachers average 190 contract days with several districts at 195 or above (Mehlville, Brentwood, Lindbergh). In looking through the state numbers, some districts only required 175 or even 174 (!) days. That's as much as a four week difference. Yes, the urban districts pay more, but they also expect more of their teachers. Since Missouri's minimum number of school days is 174, some of the rural districts must not have any or minimal professional development days. I think this needs to be addressed in any minimum salary legislation.
Numbers taken from MSTA Mo. Salary Schedule and Benefits Report