Sen. Barbara Mikulski (D-Md.) holds the distinction of being the first senator to offer a successful amendment to the big Senate health-care overhaul bill now being debated in Washington, D.C. It is a perfect lesson in what’s wrong with the political mentality.

According to Mikulski’s news release, the amendment would “guarantee women access to preventive health care screenings and care at no cost ... [by requiring] all health plans to cover comprehensive women’s preventive care ... with no copayments.” (Emphasis added.)

Does this amendment make Mikulski a great humanitarian? It may appear so on the surface. But if we stay at the surface of public policy we miss many important details.

The first thing to notice is that it would require all plans to include comprehensive women’s preventive services. Why a single man would want those included in his medical coverage is something only a politician can explain.

But, you say, what’s the big deal? If it’s “at no cost” with “no copayments,” who cares?

And that brings us to the main point. What does “at no cost” mean? Is Mikulski offering to pay personally for every women’s preventive services? If so, all I can say is that it is very generous of her. But I have a feeling that that is not what she means.

All we know is that under her amendment women would not have to pay explicitly for the services they receive. Their employers would not even be allowed to openly deduct some of the plan’s premium from their paychecks.

But that raises a problem that Mikulski was apparently never asked about. No matter what her amendment says, preventive services such as mammograms do have costs. The required equipment doesn’t just wash onto shore. It has to be produced, which takes scarce labor and resources. In other words, we have to give up something else when the equipment is produced. Moreover, the doctors and technicians who administer the tests would like to be paid for their services. If they aren’t, they will very likely do something else to make a living.

So there are costs for preventive services whether we choose to acknowledge them or not. The health-care discussion tends to overlook a rather elementary fact: Costs don’t vanish simply because Congress decrees that a particular set of persons won’t have to face them. Someone else will. Why is it preferable that some faceless unknown set of persons pay rather than those who choose to receive the services?

Actually, even the group that Mikulski wants to help is likely to end up paying at least some of the costs. But since those costs will be hidden, women won’t realize how much they’re paying and Mikulski will maintain her hero status.

Insurance companies — surprise! — will want to be reimbursed for the services they pay for — they’re businesses, not charitable organizations. So they will have to raise premiums to employers. But then employers, who will have to pay more for their workers’ medical coverage, will have less money for cash wages. So “free” preventive services will translate into lower pay, smaller raises, or even fewer jobs. Maybe women would rather have the cash than the services (which they could pay for out of pocket after shopping around). Doesn’t it demean women when politicians make those decisions for them?

Even in cases where the costs are shifted to men, we should ask whether it is fair. It is entirely likely that higher-income women will get their preventive services at the expense of lower-income men. Is that what we want?

Mikulski’s amendment illustrates how irresponsible politicians are. It is so easy for them to stand on the floor of the House or Senate and “give” things away for free, with no thought to who will actually have to swallow the expense. Why do we tolerate that? At the very least, we ought to know how much the government costs us, but we can’t know as long as politicians can do what Mikulski and her colleagues have done.

Here’s a modest suggestion to help control the cost. Every bill and amendment that purports to give something away for free should be required to specify where the money would come from.

Is that asking too much?