Economist: by 2018, Boomer retirement costs could swallow 18% of GDP

"With each passing year, those Social Security and Medicare payouts will multiply greatly so that by about 2030, they will be gobbling some 18% of the country's gross domestic product. That would amount to just about all -- that's right, all -- the tax revenues collected by the government, according to economist Rudy Penner, a deficits expert at the Urban Institute in Washington D.C. " "The Budget Deficit: Hopeless but not Serious...Yet" Marketwatch