What does it mean for the state to “underfund” education?

Source: Show-Me Institute
by James V Shuls, PhD

“A new budget proposal from Rep. Scott Fitzpatrick (R-Shell Knob) would fully fund Missouri’s foundation formula for K-12 education for the first time in years. … The fact that Missouri has not fully funded the formula has been a rallying cry for more education spending. Indeed, educators across the state have claimed that we are ‘underfunding public education.’ This new budget proposal has me wondering what will happen to those calls for increased spending when the state finally does fully fund the formula. Will they die down, or will they persist? To answer this question, it is important to define ‘underfunding’ public education.” (03/17/17)