The aim of the concept of potential – as opposed to actual – GDP is to take into account that, like an engine, an economy often operates below or above potential. In a demand-driven recession, actual output falls below potential, which results in a rise in unemployment.
潜在GDP——相对于实际GDP——的概念是为了考虑经济就像是发动机，常常出现低负荷或超负荷运转的情况。在需求导致的衰退中，实际产出低于潜在产出，导致失业增加。类似地，在信用助长的建筑业繁荣中，产出会高于潜在水平，导致通货膨胀。