Voters will decide next month whether to change the Illinois Constitution so that it's harder to improve retirement benefits for public employees. Basically, the amendment would require a three-fifths vote instead of a simple majority for any pension increase.

Illinois pension systems are in a financial mess, and some critics say legislators too often grant better benefits without worrying about the cost. The amendment is supposed to encourage consensus and keep the majority party from ramming a bill through the Legislature.

But it's not clear how much the amendment could help.

Most pension "sweeteners" have been approved by overwhelming majorities.

And the increases are a small part of the financial problem. They account for only 9% of growth in the pension shortfall over the past 15 years.