The Sanders Institute has an economic study out on what the macroneconomic effects of full student debt cancellation would be. From the executive summary:
More than 44 million Americans are caught in a student debt trap. Collectively, they owe nearly $1.4 trillion on outstanding student loan debt. Research shows that this level of debt hurts the US economy in a variety of ways, holding back everything from small business formation to new home buying, and even marriage and reproduction. It is a problem that policymakers have attempted to mitigate with programs that offer refinancing or partial debt cancellation. But what if something far more ambitious were tried? What if the population were freed from making any future payments on the current stock of outstanding student loan debt? Could it be done, and if so, how? What would it mean for the US economy?
Read the entire study here: http://wellstoneclub.org/download/sanders-institute-study-on-student-debt-cancellation/?wpdmdl=1590