Essays on efficiency of capital markets

This PhD thesis comprises three research papers that contribute to the literature on market efficiency. All papers cover some aspects of the arbitrage process. The first paper, titled "A Name That Rings a Bell: Spillover Effects in Companies with Similar Names", documents irrational spillover effects in equity markets due to similarities in company names. It shows that investors' confusion of company names is a source of uninformed demand shocks that drive prices away from their fundamental levels. These price deviations are the first aspect of the arbitrage process. The second paper, titled "Do Short Sellers Exploit Stock Mispricing Smartly?", demonstrates that market participants who engage in short selling identify and exploit market anomalies and, as a result, contribute to market efficiency. Thus, this paper shows that arbitrageurs are able to identify stock misvaluations and, at least partially, push the prices back to their fundamental levels, which is the second aspect of the arbitrage process. Finally, in the third paper, titled "Surprise in Short Interest", I construct a new measure of informed short selling and find that information contained in this measure is not fully priced by market participants. The results imply that limits to arbitrage, at least partially, hinder other investors from following short-sellers' positions that are associated with abnormal returns. This type of market friction prevent prices from converging to their fair values over extended period of time. Thus, the last paper highlights market frictions as an important third aspect of the arbitrage process. I summarize all three papers in more details below