Investors in 401(k) plans violate basic principles of diversification by holding a significant fraction of their savings in the form of their employers' equity. This paper characterizes investors' active changes to their company stock investment over time by analyzing new inflows and transfers....

We study optimal liquidity trading in a framework where trade size has a price impact. A liquidity trader wishes to trade a fixed number of shares within a certain time horizon and to minimize the mean and variance of the costs of trading. Explicit formulas for the optimal trading strategies...

Consider a trading environment where trading volume affects security prices. We show that when the price impact is time stationary, only linear price-impact functions rule out arbitrage. This is true whether a single asset or a portfolio of assets is traded. When the temporary and permanent...

We examine the geographic distribution of the shareholders of the U.S. Regional Bell Operating Companies (RBOCs) and document that a customer of an RBOC is more likely to invest in his local company than in an RBOC in another service area. Holdings of the local RBOC tend to be larger than...

Building on recent developments in behavioral asset pricing, we develop a model in which dispersion of investor beliefs under short-selling constraints drives a firm's stock price above its fundamental value. Managers optimally respond to the stock market bubble by issuing new equity. The bubble...