The business cycle is alive and well, and real variables respond to it more or less as they always did. Witness the Great Recession. Inflation, in contrast, has gone quiescent. This paper studies the sources of this disconnect using vector autoregressions and an estimated dynamic stochastic general equilibrium model. It finds that the disconnect is due primarily to the muted reaction of inflation to cost pressures, regardless of how they are measured—a flat aggregate supply curve. A shift in policy toward more forceful inflation stabilization also appears to have played some role by reducing the impact of demand shocks on the real economy. The evidence rules out stories centered around changes in the structure of the labor market or in how we should measure its tightness.

商业周期是一个活跃而良好的过程，实际变量或多或少会像往常一样对它做出响应。见证大萧条。相反，通货膨胀已经停滞不前。本文使用向量自回归和估计的动态随机一般均衡模型研究了这种断开的原因。研究发现，这种脱节主要是由于通货膨胀对成本压力的反应减弱，而不管它们如何衡量-总供给曲线平坦。通过降低需求冲击对实体经济的影响，朝着更强有力的通货膨胀稳定化的政策转变似乎也起到了一定作用。证据排除了围绕劳动力市场结构变化或我们应如何衡量其紧张程度的故事。