The Conference Board's Consumer Confidence Index declined in June to just 50 percent, its lowest level in 16 years and about half of what it was a year ago. That's not surprising given rising food costs, skyrocketing oil prices and home-mortgage troubles.

It's tempting in such situations for voters to demand action from Washington. And the politicians, as we are now seeing, usually are happy to oblige. Days before adjourning for their summer recess, for example, Congress passed a huge $300 billion bailout bill to help homeowners and mortgage lenders.

But government action comes at a cost. While so-called government rescue programs may ease some of today's problems, they often make the situation worse in the long-run.

During this campaign season in particular, we all need to remember that the United States historically has had one of the strongest economies in the world. One reason for this is America's comparatively low tax rates.

A recently released British study compared the economic performance of 10 high-tax countries and 10 low-tax countries and found a strong correlation between low taxes and high rates of economic growth. What this should tell politicians is: If government needs additional revenues, it should be cutting taxes, not raising them.

Conducted by economist Keith Marsden for the London-based Center for Policy Studies, the tax-comparison study found that countries with lower tax rates outperform high-tax countries.

While "high" and "low" are somewhat subjective terms, Marsden identified Australia, Canada, Estonia, Hong Kong, Ireland, South Korea, Latvia, Singapore, Slovakia and the United States as relatively low-tax countries. Austria, Belgium, Denmark, France, Germany, Italy, Netherlands, Portugal, Sweden and the United Kingdom were identified as high-tax countries.

The countries with lower tax rates had an average 30 percent top personal income-tax rate and an average 22 percent top business-tax rate. The high-tax countries had an average top personal income-tax rate of 45 percent and a top corporate tax rate of 29 percent, more than 30 percent higher.

Marsden's findings were dramatic, though not necessarily surprising. In the low-tax countries, he found that Gross Domestic Product increased on average 5.4 percent per year during the period 1998 through 2007. By comparison, GDP increased in the higher-tax countries at an average annual rate of just 2.1 percent, less than half.

Low-tax countries also increased their exports at more than double the rate of the high-tax countries, averaging 6.3 percent annual growth from 2000 to 2005, compared to 3.1 percent in the high-tax countries. Not surprisingly, investors were far more attracted to and far more willing to risk their money in the low-tax economies than the high-tax countries. Investment increases averaged 5.9 percent per year from 2000 to 2005 in the low-tax countries and just 0.8 percent per year in the high-tax economies - a more than sevenfold difference.

From 2000 to 2005, the low-tax countries increased spending on public services an average of 3.4 percent per year, while the high-tax countries increased spending 1.7 percent per year on average.

Fiscal policy, of course, is not the only factor affecting GDP, job, investment and export growth. Regulatory policy, monetary policy and other factors also are important. Yet, at the end of the day, Marsden showed, a simple truth exists: If you want more of anything, whether it's government revenue or jobs, you tax it less. If you want less of anything, you tax it more.

It's a lesson this election season that Sens. Barack Obama and John McCain both should heed.