Sorry, Dems, but a VAT won't work

Left alone, government would grow larger. From 1970 to 2009, federal spending averaged 20.7 percent of the economy (gross domestic product). By 2020, it could reach 25.2 percent of GDP and would still be expanding, reckons the Congressional Budget Office’s estimate of President Obama’s budgets. In 2020, the deficit (assuming a healthy economy with 5 percent unemployment) would be 5.6 percent of GDP. To cover that, taxes would have to rise almost 30 percent.

A VAT could not painlessly fill this void. Applied to all consumption spending — about 70 percent of GDP — the required VAT rate would equal about 8 percent. But the actual increase might be closer to 16 percent because there would be huge pressures to exempt groceries, rent and housing, health care, education and charitable groups. Together, they account for nearly half of $10 trillion of consumer spending. There would also be other upward (and more technical) pressures on the VAT rate…

Higher consumer prices from the VAT could also slow the economy. The Federal Reserve would face policy dilemmas. If it tried to prevent businesses from passing along the tax to consumers, it would have to raise interest rates and risk a recession. If it tried to blunt the effect of higher prices on spending, its easy credit policy might trigger a new wage-price spiral.