国际金融危机以来,美国深陷高赤字、高失业、低增长的“两高一低”的经济困局。对美国财政政策的研究表明,提振经济的扩张性财政政策受到法定债务上限的制约,美国面临着财政政策的选择困境。对美国货币政策的研究表明,零利率政策由于信号效应的损失不但未能有效产生预期政策效果,而且丧失了后续操作空间;两轮量化宽松货币政策因流动性陷阱而不具备长效性;“扭曲操作”本质上不可能改变美国的经济走势,因此美国也面临着货币政策的选择困境。深陷经济困局、面临经济政策选择困境的美国,未来在维持扩张性货币政策的同时,可能将进入财政政策的紧缩期,其最坏的结果是将美国经济拖入长期“滞涨”。 Since the international financial crisis, the United States has been stuck in an economic dilemma of “two highs and one low” with high deficits, high unemployment and low growth rates. Studies on the U.S. fiscal policy show that the expansion of the fiscal-boosting economy is constrained by the statutory debt ceiling, and the United States is faced with the dilemma of choosing fiscal policies. The research on the U.S. monetary policy shows that the loss of the zero-interest-rate policy not only failed to produce the desired policy effect effectively, but also loses follow-up operation space. The two rounds of quantitative easing monetary policy do not have the long-term effect due to the liquidity trap. “Distortion Operation” is virtually impossible to change the economic trend in the United States. Therefore, the United States is also faced with the dilemma of choosing monetary policy. In the future, while maintaining its expansionary monetary policy, the United States facing economic dilemmas and its predicament in the choice of economic policies may enter into the austerity period of fiscal policy. Its worst outcome will be to drag the U.S. economy into a long-term “stagflation” ".