The importance of economically sound and science-based regulations cannot be overstated.

Too often, however, history has shown how government rulemaking can have perverse consequences because those promulgating the rules didn’t think things through.

An excellent case in point emerged recently when the trade group for the home appliance industry warned that the Obama administration’s proposed dishwasher efficiency standards might produce no discernible improvements in efficiency – and may lead consumers to use more energy and more water, even as their tempers flare.

How come? Because the new standards are too strict to clean dishes well.

Manufacturers have already begun tweaking their models to comply with the new government requirements, which permit only 3.1 gallons of water per load of dishes. But in standard testing with food stuck to dishes, “they found some stuff that was pretty disgusting,” according to an official with the Association of Home Appliance Manufacturers.

The group invited government officials to view their tests and showed that consumers will likely need to re-wash dishes, thereby erasing any efficiency gains.

A similar case is emerging with the administration’s proposed ozone regulations I wrote about the other day.

A Chamber of Commerce event highlighted the fact that federal transportation funding could be withheld from regions failing to comply with the overly strict standard. (More than 350 U.S. counties are expected to be in violation if EPA’s 70 parts per billion ozone standard becomes law, with an additional 550 in violation at 65 ppb. Many U.S. regions could see needed highway projects cancelled.)

Panelist Richard Parsons of the Suburban Maryland Transportation Alliance made an astute observation that appears to have been lost on those at the Environmental Protection Agency pushing the new standard.

Mr. Parsons noted that the most needed transportation projects in Washington, D.C. – as in many municipal regions – are those designed to alleviate traffic snarls, gridlock, and bad commutes.

That’s important since cars idling in traffic are a major source of ground-level ozone. Cars that move faster are responsible for far less ozone, so alleviating major traffic problems would help clean the air.

But what happens if the new ozone standard – which in theory is designed to improve air quality – leads to needed highway projects getting cancelled in D.C. and elsewhere?

Bad traffic will worsen, along with a region’s air quality. And all because of poorly thought-out regulation ostensibly designed to improve the situation.

No wonder Mr. Parsons described EPA’s proposed stricter standard as “a nonsensical sanction that could make things worse.”

These two cases underscore that you can’t merely wish regulatory improvements into existence. Such improvements can only come about as the result of a regulatory process that takes real-world considerations and consumer reactions into account.