I identify three option exercise strategies executives engage in, including (i) exercising with cash and immediately selling the shares, (ii) exercising with cash and holding the shares, and (iii) delivering some shares to the company to cover the exercise costs and holding the remaining shares. Stock price patterns suggest executives manipulate option exercises. They use private information to increase the profitability of all three strategies, and likely backdated some exercise dates in the pre-Sarbanes-Oxley period to enhance the profitability of the latter two strategies, where the executive's company is the only counterparty. Backdating is associated with reporting of internal control weaknesses.

Stock-market trading is increasingly dominated by sophisticated professionals, as opposed to individual investors. Will this trend ultimately lead to greater market efficiency? I consider two complicating factors. The first is crowding—the fact that, for a wide range of “unanchored” strategies, an arbitrageur cannot know how many of his peers are simultaneously entering the same trade. The second is leverage—when an arbitrageur chooses a privately optimal leverage ratio, he may create a fire-sale externality that raises the likelihood of a severe crash. In some cases, capital regulation may be helpful in dealing with the latter problem.

ABSTRACT Stock‐market trading is increasingly dominated by sophisticated professionals, as opposed to individual investors. Will this trend ultimately lead to greater market efficiency? I consider two complicating factors. The first is crowding—the fact that, for a wide range of “unanchored” strategies, an arbitrageur cannot know how many of his peers are simultaneously entering the same trade. The second is leverage—when an arbitrageur chooses a privately optimal leverage ratio, he may create a fire‐sale externality that raises the likelihood of a severe crash. In some cases, capital regulation may be helpful in dealing with the latter problem.

The acceleration of the U.S. productivity growth in the late 1990s suggests a significant advance in technological innovation, making the perceived probability of entering a “new economy” ever increasing. Based on macroeconomic data, we identify a Bayesian investor's belief evolution when facing a possible structural break in the economy. We show that such belief evolution plays a significant role in explaining both the stock market boom and crash during 1998 to 2001. We conclude that a rational investor's uncertainty about the future of the U.S. economy provides an alternative explanation for the late 1990s stock market “bubble.”

ABSTRACT The acceleration of the U.S. productivity growth in the late 1990s suggests a significant advance in technological innovation, making the perceived probability of entering a “new economy” ever increasing. Based on macroeconomic data, we identify a Bayesian investor's belief evolution when facing a possible structural break in the economy. We show that such belief evolution plays a significant role in explaining both the stock market boom and crash during 1998 to 2001. We conclude that a rational investor's uncertainty about the future of the U.S. economy provides an alternative explanation for the late 1990s stock market “bubble.”

ABSTRACT I identify three option exercise strategies executives engage in, including (i) exercising with cash and immediately selling the shares, (ii) exercising with cash and holding the shares, and (iii) delivering some shares to the company to cover the exercise costs and holding the remaining shares. Stock price patterns suggest executives manipulate option exercises. They use private information to increase the profitability of all three strategies, and likely backdated some exercise dates in the pre‐Sarbanes‐Oxley period to enhance the profitability of the latter two strategies, where the executive's company is the only counterparty. Backdating is associated with reporting of internal control weaknesses.

We report evidence on the determinants of whether the relationship between a firm and its Chief Executive Officer (CEO) is governed by an explicit (written) or an implicit agreement. We find that fewer than half of the CEOs of S&P 500 firms have comprehensive explicit employment agreements. Consistent with contracting theory, explicit agreements are more likely to be observed and are likely to have a longer duration in situations in which the sustainability of the relationship is less certain and where the expected loss to the CEO is greater if the firm fails to honor the agreement.

We show that individual investors over-extrapolate from their personal experience when making savings decisions. Investors who experience particularly rewarding outcomes from 401(k) saving—a high average and/or low variance return—increase their 401(k) savings rate more than investors who have less rewarding experiences. This finding is not driven by aggregate time-series shocks, income effects, rational learning about investing skill, investor fixed effects, or time-varying investor-level heterogeneity that is correlated with portfolio allocations to stock, bond, and cash asset classes. We discuss implications for the equity premium puzzle and interventions aimed at improving household financial outcomes.

ABSTRACT We report evidence on the determinants of whether the relationship between a firm and its Chief Executive Officer (CEO) is governed by an explicit (written) or an implicit agreement. We find that fewer than half of the CEOs of S&P 500 firms have comprehensive explicit employment agreements. Consistent with contracting theory, explicit agreements are more likely to be observed and are likely to have a longer duration in situations in which the sustainability of the relationship is less certain and where the expected loss to the CEO is greater if the firm fails to honor the agreement.