The real side of stock market exuberance: bubbles, output and productivity at the industry level
研究股市泡沫对行业产出、投入和生产率的影响，发现泡沫扩张期产出和投入增长加快，但全要素生产率增长放缓，增长主要来自要素积累而非生产率提升。
Abstract There has been a growing interest in the theory of rational bubbles. Recent theories predict that bubbles are expansionary, but differ in the underlying mechanisms. This paper provides empirical evidence that helps us to assess different theories, and documents four main findings: stock market overvaluation is associated with (i) faster output and input growth, (ii) declining total factor productivity (TFP) growth, (iii) a greater contribution of labour and a declining contribution of TFP for output growth, (iv) an increase in the number of firms. Overall, these findings suggest that bubbly expansions are driven by increased factor accumulation (in particular labour), and not from higher productivity growth.