A private sector worker has three sources of retirement income. He has Social Security, his own savings plan, and probably a company pension. Teachers do not get any Social Security benefits, so they rely heavily on a good pension plan. So, if you do away with the union's right to collectively bargain benefits, some teachers may be without retirement benefits that private-sector workers have.Spondike raises a great point. Here's some relevant info from the New York Times:
More than six million public employees work outside the Social Security system, including roughly 1.7 million teachers in California, Illinois and Texas, and nearly two million employees of all types in Alaska, Colorado, Massachusetts, Nevada and Ohio, as well as Louisiana and Maine. For years, these and other states have insisted they could provide richer pensions at a lower cost, both to workers and taxpayers, because of investments.So: States promised big pensions to state workers who stayed off Social Security because it was cheaper. But the states failed to put enough money away to cover their promises. And now the states want to reneg on those promises because of "shared sacrifice." That means the states get teacher's services for lower cost than what those states valued those services at, both on the front end and the back end. And yet it's the union members—not state officials—who are being maligned.
Some of those states’ pension plans now have shortfalls so large that they need outsize contributions. Virtually all state pension funds have had big losses in the last two years, but the go-it-alone states appear especially vulnerable.