The Social Cost of Near-Rational Investment
研究发现，即使股票市场看似有效，也可能无法有效汇聚信息，导致价格信息含量下降，进而加剧不确定性，扭曲消费、资本积累和劳动力供给，降低社会福利。
We show that the stock market may fail to aggregate information even if it appears to be efficient, and that the resulting decrease in the information content of prices may drastically reduce welfare. We solve a macroeconomic model in which information about fundamentals is dispersed and households make small, correlated errors when forming expectations about future productivity. As information aggregates in the market, these errors amplify and crowd out the information content of stock prices. When prices reflect less information, the conditional variance of stock returns rises, causing an increase in uncertainty and costly distortions in consumption, capital accumulation, and labor supply.