The stock market should fund promising new firms, thereby breeding competition, innovation, and economic growth. However, using three decades of data from 47 countries, we show that concentrated stock markets dominated by a small number of very successful firms are associated with less efficient...

We provide strong support for the underappreciated expected earnings hypothesis of negative correlation between aggregate stock returns and earnings (Sadka and Sadka (2009); Choi, Kalay, and Sadka (2016)). For the 1970 to 2000 period studied by Kothari, Lewellen, and Warner (2006), our powerful...