In a desperate search for money to fill the holes in the state budget, Massachusetts lawmakers are looking for new ways to tax.

Among the proposals floated in a recent subcommittee hearing was expanding the state sales tax to include services.

That's a bad idea that Massachusetts taxpayers have had to beat down once before. If the tax-and-spenders on Beacon Hill have their way, we will have to do it again.

In Massachusetts, sales taxes apply to goods sold. Services, such as haircuts or having one's taxes prepared by an accountant, are exempt.

Now legislators are poring over the list of tax exemptions in search of those they can eliminate. They're getting desperate, as the state's revenues continue to fall short of projections. Just a few months into the 2010 fiscal year, and lawmakers are already looking at a budget shortfall of $600 million.

The exemption from the sales tax for services saves taxpayers $6 billion a year.

Of course, legislators lined up a panel of experts at a recent hearing to tell them what they wanted to hear.

"I think it's crazy," said Karl Case, a Wellesley College economics professor, as reported by the State House News Service. "What's the difference between a good and service today? I never quite understood why it's there."

Here's one difference the professor may not be aware of. Dozens of Massachusetts towns — our local towns included — are close enough to the New Hampshire border to make taxes like this a serious economic threat. Many people already go over the border to buy tax-exempt goods, and Massachusetts lawmakers gave people an additional incentive earlier this year when they raised the sales tax and placed a new sales tax on liquor. That move has particularly hurt liquor stores in communities like Amesbury, Salisbury and Newburyport. Adding a whole new segment of businesses to this sales exodus will cause further erosion, especially in downtowns like Amesbury and Newburyport, where service-related businesses are a major part of the local economy.

If lawmakers decide to tax services, they may as well call the bill the "New Hampshire Stimulus Act."

Legislators tried this once before. In the early 1990s, former state Sen. Patricia McGovern, D-Lawrence, led the drive for a tax on services. Billed as a tax on "the rich," lawmakers soon realized the levy would apply to nearly all services used by rich and poor alike. They repealed the measure shortly after it took effect.

The Legislature's dream of millions from the increased sales tax has been a nightmare. Since the tax was hiked to 6.25 percent, sales tax revenues have fallen. In September, sales tax revenues were $37 million below expectations.

Don't let legislators make the same mistake with services and drive our economy into an even deeper hole.