One classic example of government doing it better is health insurance. Yes, conservatives constantly agitate for more privatization — in particular, they want to convert Medicare into nothing more than vouchers for the purchase of private insurance — but all the evidence says this would move us in precisely the wrong direction. Medicare and Medicaid are substantially cheaper and more efficient than private insurance; they even involve less bureaucracy. Internationally, the American health system is unique in the extent to which it relies on the private sector, and it’s also unique in its incredible inefficiency and high costs.

And there’s another major example of government superiority: providing retirement security.

Maybe we wouldn’t need Social Security if ordinary people really were the perfectly rational, farsighted agents economists like to assume in their models (and right-wingers like to assume in their propaganda). In an idealized world, 25-year-old workers would base their decisions about how much to save on a realistic assessment of what they will need to live comfortably when they’re in their 70s. They’d also be smart and sophisticated in how they invested those savings, carefully seeking the best trade-offs between risk and return.

In the real world, however, many and arguably most working Americans are saving much too little for their retirement. They’re also investing these savings badly. For example, a recent White House report found that Americans are losing billions each year thanks to investment advisers trying to maximize their own fees rather than their clients’ welfare.

You might be tempted to say that if workers save too little and invest badly, it’s their own fault. But people have jobs and children, and they must cope with all the crises of life. It’s unfair to expect them to be expert investors, too. In any case, the economy is supposed to work for real people leading real lives; it shouldn’t be an obstacle course only a few can navigate.

And in the real world of retirement, Social Security is a shining example of a system that works. It’s simple and clean, with low operating costs and minimal bureaucracy. It provides older Americans who worked hard all their lives with a chance of living decently in retirement, without requiring that they show an inhuman ability to think decades ahead and be investment whizzes as well. The only problem is that the decline of private pensions, and their replacement with inadequate 401(k)-type plans, has left a gap that Social Security isn’t currently big enough to fill. So why not make it bigger?