Otis White, over on our "Urban Notebook" page, makes a point about units of local government in St. Louis that is worth highlighting:
"St. Louis has the second-highest ratio of local governments to citizens (31.7 per 100,000 population, second only to Pittsburgh). Your assumption: People must pay a lot for all these governments. Nope. St. Louis is fourth from the bottom for the percentage of total personal income claimed by local government."
That's significant, because one of the arguments you'll always hear made by proponents of regionalism is that merging services or agencies will save money. It can be done where there are duplicative services. But promises of monetary savings are usually overblown.
That doesn't mean there aren't other good reasons to combine governments, such as efficiency or making the lines of decision-making more clear.