The top 10 most expensive U.S. colleges of 2012

The top 10 most expensive U.S. colleges of 2012 http://bit.ly/VwPcps

I wonder if these universities' tuition fees are due to the professors who are employed or if they are due to the fact that students can take loans. I think that tuition fees in the US could be lowered if it was not possible to get a loan to go to college.