In a speech before the Daimler Trucks North America manufacturing plant in Charlotte, N.C. today, the president delivered his answer to rising gas prices: He wants to increase the $7,500 tax credit for alternative-energy vehicles to $10,000, earmark $1 billion to reward cities that provide infrastructure for such vehicles, earmark an additional $650 million for a research program to increase the range and decrease the price of the vehicles, and repeal $4 billion of tax incentives for oil and gas companies.

Why? Here is a telltale paragraph from The New York Times:

The credit’s enhanced value would bring the purchase price of alternative-energy vehicles more in line with conventional models, supporters say. Partly because of the vehicles’ costs, sales have been a problem. General Motors announced last week that it was suspending production for five weeks of the Chevrolet Volt, a plug-in hybrid that Mr. Obama has promoted in the past. On Wednesday, he did not mention his goal of having one million electric vehicles on the nation’s roads in 2015.

So, supporters admit that, right now, the benefits of alternative-energy vehicles don’t yet outweigh the costs to consumers. To the producers of such vehicles, I say: Tough luck. The onus is on them to produce a product that consumers actually want to purchase at a price they can afford. Tax credits might give consumers more reason to purchase the vehicles, but it won’t give the producer any incentive to look for cheaper ways to manufacture them. The president’s tax credit ensures that taxpayers will continue to pay an arbitrarily high price for the vehicles long after the market would have brought costs down.

The tax code exists to raise revenue so the federal government can fulfill certain basic, essential functions that individuals or state and local governments cannot (like defend the nation from its enemies!). Tax credits, tax subsidies and tax penalties turn the tax code into an instrument to manipulate behavior instead. That some Republicans favor tax credits for oil and gas companies and that some Democrats favor tax credits for alternative energy companies reveals the problem inherent in the use of the tax code for such behavior manipulation: It leaves it up to politicians in Washington to determine what behavior is desirable. Let the people decide instead.