Unrealistic assumptions and missed investment returns have meant Illinois taxpayers paid $13.7 billion more for public pensions than state leaders projected five years earlier. Unless the estimates improve, taxpayers will pay an extra $21.3 billion during the next decade.

Illinois’ current budget started out at a deficit, hoped for a tax increase that was rejected and counted on a federal bail-out that never came. Gov. J.B. Pritzker’s best fix is pension reform.