The number of Americans without health insurance has grown by nearly 8 million since 2001 to 46 million today.

The moral cost of this failure can be measured in the growing numbers of adults and children who go without checkups and other basic and preventive care, leaving them vulnerable to serious illness and struggling at school or work because of minor problems that easily could be cured with a doctor visit.

Now the economic imperative is coming into sharper focus as well. A new report by Families USA, an advocate for universal health care coverage, shows the financial stake all Americans have in expanding coverage as part of President Barack Obama's proposed health care reforms.

The report demonstrates that the so-called "hidden health tax" — the cost paid by insured Americans to subsidize care for the uninsured — grew to $1,017 for the typical family of four in 2008, up from $922 in 2005. As the ranks of the uninsured explode during this recession, those numbers are sure to skyrocket.

The conclusion is obvious. Rather than facing higher costs because of health care reform, taxpayers could see their overall financial outlook improve if we had a more efficient system of providing basic care to all Americans.

Here's how the hidden tax works.

By law, hospitals must help anyone who walks into an emergency room. That isn't going to change anytime soon, nor should it in a humane, first world nation.

The cost of providing that care to the uninsured was an estimated $42.7 billion in 2008. Taxpayers pick up part of the cost at public hospitals, but insured Americans bear a significant burden in higher insurance premiums and higher costs for medical services, all to help make up for the bills the uninsured can't pay.

Critics of reform often say they don't want their money going to help undocumented immigrants, but they're already paying the cost of emergency room visits. However, it's a misconception that most of the uninsured are undocumented. The vast majority — roughly 85 percent — are citizens or legal residents, and that proportion will likely grow as the recession drags on.

Emergency room care remains one of the most expensive and least efficient ways to treat routine illnesses. It's the medical equivalent of seeing the red light come on your car dashboard and not doing anything about it until you're stalled on the freeway, with your engine burned out. People who have insurance can heed that red light and seek help earlier, at a doctor's office or clinic, at far lower cost, which most often prevents more serious conditions.

Obama is committed to enacting health care reform this year because he sees it as a key to repairing the economy. He's pushing Congress to produce bills before the summer recess in August, and he has outlined some basic principles, which Congress should embrace. These include reining in costs and making sure Americans have a choice of doctors and health plans through a mix of affordable private and public offerings.

Controlling costs is essential. The United States spends about $2.5 trillion a year on health care, far more per capita than its European counterparts, even though nearly all European nations have some form of universal coverage. Making wiser use of U.S. health care dollars will benefit not only Americans' health but their wallets as well.