从2008年开始的世界金融危机仍在持续，对世界经济造成巨大影响。在这次金融危机中，传统产出缺口理论遭遇巨大挑战，直接测算与间接标示都未能成功预测危机，原有应对政策的效力也大幅下降。传统测算方法的问题、菲利普斯曲线的平缓化、均衡利率的持续下降等问题在危机前就已存在，并经危机更加凸显，这是传统产出缺口研究失效的一个重要原因。此外，危机中金融因素对产出缺口测算的影响、对通胀盯住制的削弱、对利率调节的限制则是原有理论失灵的另一重要缘由。要应对产出缺口研究出现的问题以及危机后实际产出增速的放缓，不仅要在凯恩斯主义政策框架内改善产出缺口的状况，还要从结构主义的视角解决潜在产出的变化问题。

 

Traditional output gap theory suffered great challenges during global financial crisisNeither varieties of gap estimation methods succeeded in predicting the crisis, nor the macro policy retained effectiveness in crisis rescueThe failure of traditional output gap theory can be partly attributed to some problems that have existed before the crisis, such as the defects of gap estimation methods, the smoother trend of Phillips curve, and the continuous declination of global equilibrium rate, and partly to some changes that have taken place during the crisis, including the influence of financial factors on output gap estimation, the weakening of inflation targeting system, and the limitation of interest rate adjustmentFaced with the problems in the traditional output gap research, we need to look back to both Keynesian and structuralism policy framework, so as to  find a way to tackle the continuous negative output gap and slower potential growth after the crisis.