The first essay finds that the market betas of value and small stocks have decreased by about 75% in the second half of the twentieth century. The decline in beta can be related to a long-term improvement in economic conditions that made these companies less risky. The failure to account for...

Private equity has traditionally been thought to provide diversification benefits. However, these benefits may be lower than anticipated as we find that private equity suffers from significant exposure to the same liquidity risk factor as public equity and other alternative asset classes. The...

In the first chapter, I study the impact of statistical arbitrage on equilibrium asset prices. Arbitrageurs have to learn about the long-run behavior of the stock price process. They condition their investment strategy on the observation of price and volume. The learning process of the...