In real life, money follows results. When an inventor creates a useful product, investors find him, market the product and sell it. There's no need for the federal government to get involved.

In fact, federal involvement usually means an approach has failed. Farmers demand subsidies, for example, when they can no longer profitably sell their crops. And some manufacturers, faced with less expensive products from overseas, demand protective tariffs.

This principle helps illuminate the ongoing debate over federal funding for embryonic stem cells to treat and cure disease. Researchers would harvest these cells from human embryos for medical treatment, destroying the embryos in the process. Despite serious ethical misgivings, some in Congress want taxpayers to spend money on it. But, at a recent panel at The Heritage Foundation, Dr. Kelly Hollowell, a molecular and cellular pharmacologist, noted that despite widespread media hype over embryonic stem-cell research, it hasn't been attracting significant private investment.

Rep. David Weldon, a Republican from Florida and a medical doctor, was on the same Heritage panel. He pointed out that science is rapidly moving away from an emphasis on embryonic stem cells and toward the study of adult stem cells. "In a few years, the embryonic people are probably going to give up," Weldon said, "because they're just not getting good research results." On the other hand, "the adult stem cell work and, in particular, the cord blood work is just phenomenal."

So there are two major research alternatives. The first is stem cells from umbilical cord blood, which are available every time a woman gives birth. The second is adult stem cells, which are typically drawn from the bone marrow of patients. The National Institutes of Health notes on its Web site: "Adult stem cells such as blood-forming stem cells in bone marrow (called hematopoietic stem cells, or HSCs) are currently the only type of stem cell commonly used to treat human diseases." They've been used for decades to treat patients with leukemia, lymphoma and several inherited blood disorders.

Embryonic stem cells, on the other hand, have yet to be successfully used to treat anything, which is why supporters want federal funding for their research effort.

Rep. Weldon said that some researchers have a selfish motive for focusing on embryonic stem cells. "If you developed a highly successful intervention for treating sickle cell anemia with cord blood, that is not really a patentable intervention under our current laws," Weldon explained. But, he noted, if someone could develop the same treatment with embryonic stem cells, that person would be a millionaire.

Still, it doesn't make a lot of sense to force taxpayers to pour money into a project that private investors have largely avoided, especially when that project isn't generating any results. It would make more sense to concentrate on stem-cell work that has proven productive and holds real promise for treating and curing disease.

If individuals, companies, universities or even state governments want to fund such research, there is nothing stopping them. California plans to spend some $3 billion on stem-cell research, including embryonic stem-cell research. In the spirit of federalism, other states may follow suit, if that's what their voters want.

But let taxpayers beware. As Rep. Weldon warns, "Taxpayers, in time, will regret that decision when they see absolutely no good cures coming out of it."

So far the debate has focused on what embryonic stem cells someday might yield. "Although [these cells] are thought to offer potential cures and therapies for many devastating diseases, research using them is still in its early stages," according to the NIH. Yet optimism runs high, as we saw recently when the House of Representatives, despite a presidential veto threat, voted 238-194 in favor of federal funding for embryonic stem-cell research.

Everyone wants to cure diseases such as Alzheimer's, Parkinson's and diabetes. But if embryonic stem cells seemed to be the singular remedy, the private research industry, including pharmaceutical companies, would be pouring money into the research. A $1 billion investment could pay 10 times that much to any company that developed a cure.

The fact that embryonic stem cell research is being left to the federal government speaks volumes.

Ed Feulner is president of the Heritage Foundation.