State public pension systems' unfunded liabilities have grown to $4.7 trillion, up from $4.1 trillion in 2013, giving them a funded ratio of just 36 percent – assuming you accept the calculations of one controversial approach. 

A nonprofit called State Budget Solutions, which has been pushing for state budget reform, arrived at that figure — it's almost five times as high as the number the states use — by using "data from over 250 state-level defined benefit pension plans holding nearly $2.6 trillion in assets" and applying a different discount rate to the one commonly used to calculate the unfunded status of a pension system. 

According to the group's report, "Promises Made, Promises Broken," instead of using discount rates based on the assumed rate of investment return, which it said is "far too risky," it discounted liabilities "based on the approximate equivalent of a 15-year U.S. Treasury bond yield."