Is a person’s decision to not buy health insurance a form of “economic activity,” subject to regulation under the U.S. Constitution’s commerce clause?

A federal judge in Virginia ruled Monday that it is not. Therefore, U.S. District Judge Henry E. Hudson wrote that a key provision of the new federal health care reform law is unconstitutional.

This ruling, however, conflicts with a federal judge in Michigan working with the same set of facts, who ruled last month that not buying health insurance is a form of economic activity. The health care reform law, which  requires everyone be covered by health insurance starting in 2014, is constitutional, according to the Michigan ruling.

As a matter of law, Monday’s unsurprising decision by Judge Hudson means the constitutionality question remains unsettled. The final word will come from the U.S. Supreme Court, as has always been expected.

As a matter of fact, however, the question was settled long ago.

Judge Hudson is entirely and demonstrably wrong. His grasp of health care economics and the realities of the marketplace are, to put it charitably, flawed. His ruling is an exercise in sophistry.

In the real world, taxpayers spend billions every year to subsidize people without health insurance.

In 2008 — before the recession sent the number of uninsured Missourians skyrocketing — 34 hospitals in the St. Louis region wrote off or received about $657 million to treat people without insurance.

That includes more than $550 million in government grants called disproportionate share payments, as well as nearly $107 million in charity care provided to poor people.

That money comes directly from taxpayers in the form of taxes and indirectly from premiums paid by people with insurance and employers who help foot the bill.

That’s just for St. Louis. The Missouri total probably is well in excess of $1 billion, and that’s just hospital care.

It doesn’t include charity care provided by doctors or nursing home care. Most nursing homes are filled with people whose care is covered by Medicaid. They didn’t have long-term care insurance. Without Medicaid, they wouldn’t get care.

Still think the decision not to buy health insurance has no economic cost on the rest of us?

The Institute of Medicine, part of the National Academies of Science, estimates that lack of health insurance costs $65 billion to $130 billion each year.

The left-leaning advocacy group FamiliesUSA estimates that families with private health insurance pay an average of $900 in higher annual premiums to cover the uninsured.

None of those estimates take into account higher costs imposed on Medicare.

A 2007 study in the New England Journal of Medicine found  that the cost to care for Medicare patients who had been uninsured before age 65 is 51 percent higher than the cost of caring for people who had health insurance.

Because Medicare spends, on average, about as much on each enrollee as it would cost to buy insurance coverage for an entire family, being uninsured imposes significantly higher costs on taxpayers.

Clearly, there’s a lot Judge Hudson doesn’t know — or that he chooses to ignore — about how we pay for health care in this country.

Just as clearly, his ruling would be a blow to the vast majority of responsible Americans who already have health insurance. They’ll have to continue footing ever-higher premiums to cover freeloaders who refuse to take responsibility for their own care.

That’s a high price to allow ideologues and activist judges a victory against common sense and needed reforms.