A few studies have been done over the years on this. One was done by an economist at UBC in the British Columbia context. Obviously it was a few years ago, so particular policies at the time were being analysed. It found that there was at least a 4:1 return on investment in post-secondary education.
A study was done by the Government of Newfoundland and Labrador on the economic and social benefits of investment in the College of the North Atlantic, which is the college system that has a number of campuses throughout Newfoundland and Labrador. It found up to an 11:1 return on investment in those communities--and it's very community focused.