> It seems to me that possibly the highest return on investment a government can do is investing in education. More intelligent people likely impacts tax revenue, crime etc. does anyone know if there are studies done on this?

I disagree, you don't need to have a smart society, you can have a moral society and that takes away a lot of government spending for the unruly. An overproduction of highly educated people doesn't make a society better if there isn't demand for those jobs.