Economist Alec Phillips said the loss "could result in a meaningfully negative effect on economic activity if not addressed quickly." But the damage would not approach the devastation to the economy from the financial crisis and its triggering event, the collapse of Lehman Brothers, according to Julian Jessop, chief global economist at Capital Economics in London. ( More : Watch Art Cashin: Why I'm a 'little anxious' now ) "Speculation that a limited default by the U.S. government would lead to a bigger financial and economic crisis than the collapse of Lehman Brothers is surely overdone," Jessop said in an analysis.