But the continuing severity of recessions in the United Kingdom and other countries pursuing fiscal contraction has suggested that multipliers are not just positive, but greater than one – just as the old wisdom had it. The International Monetary Fund has responded by forthrightly confessing that official forecasts, including its own, had underestimated the multiplier’s size.
不幸的是，很多经济学家和政治家忘了很多他们曾经学过的知识（或者说被政策失效的新理论所蒙蔽了）。事实上，在2008-2009年全球危机爆发时，即便是财政刺激的拥护者也调低了对乘数的估算。而英国以及其他追求财政紧缩国家的持续严重衰退，这表明了乘数不仅是正数而且还大于1——正如以往的经验所示。国际货币基金组织也坦率承认各地的官方预测——包括它自身的预测，都低估了乘数的效应。