EVEN WITH ROSY ASSUMPTIONS, public pensions are deep in the red. “A 2010 Pew study on public pensions nationwide put the funding gap at about a half-trillion dollars based on states’ own assumptions. But Novy-Marx and North western University’s Joshua Rauh say it’s $3 trillion using a risk-free discount rate.” I think a 4% rate is realistic. But note how bad things look assuming even a 6% return.