[This article investigates the dynamic relation between market-wide trading activity and returns in 46 markets. Many stock markets exhibit a strong positive relation between turnover and past returns. These findings stand up in the face of various controls for volatility, alternative definitions of turnover, differing sample periods, and are present at both the weekly and daily frequency. The relation is more statistically and economically significant in countries with high levels of corruption, with short-sale restrictions, and in which market volatility is high.]

[We examine whether spin-offs or divestitures cause improvements in conglomerate investment efficiency. At issue are endogeneity of these restructuring decisions and correct measurement of investment efficiency. Endogeneity is a problem because the factors that induce firms to spin off or divest divisions may also improve investment efficiency; measurement error is a problem because efficiency measures employ Tobin's q as a noisy proxy for investment opportunities. We find important differences between firms that divest or spin off and a control sample. After accounting for these differences and for measurement error in q, we find no evidence of improvements in investment efficiency.]

[Agency problems limit firms' access to capital markets, curbing investment. Firms and investors seek contractual ways to mitigate these problems. What are the implications for investment? We present a theory of a firm's investment dynamics in the presence of agency problems and optimal long-term financial contracts. We derive results relating firms' investment decisions, current and past cash flows, firm size, capital structure, and dividends. Among the results, optimal investment is increasing in current and past cash flow; and optimal investment is positively serially correlated over time (after controlling for investment opportunities). These results hold for a range of agency problems.]

[We develop an agency model of financial contracting. We derive long-term debt, a line of credit, and equity as optimal securities, capturing the debt coupon and maturity; the interest rate and limits on the credit line; inside versus outside equity; dividend policy; and capital structure dynamics. The optimal debt-equity ratio is history dependent, but debt and credit line terms are independent of the amount financed and, in some cases, the severity of the agency problem. In our model, the agent can divert cash flows; we also consider settings in which the agent undertakes hidden effort, or can control cash flow risk.]

This article investigates the dynamic relation between market-wide trading activity and returns in 46 markets. Many stock markets exhibit a strong positive relation between turnover and past returns. These findings stand up in the face of various controls for volatility, alternative definitions of turnover, differing sample periods, and are present at both the weekly and daily frequency. The relation is more statistically and economically significant in countries with high levels of corruption, with short-sale restrictions, and in which market volatility is high.

[This article shows that investors financing a portfolio of projects may use the depth of their financial pockets to overcome entrepreneurial incentive problems. Competition for scarce informed capital at the refinancing stage strengthens investors' bargaining positions. And yet, entrepreneurs' incentives may be improved, because projects funded by investors with "shallow pockets" must have not only a positive net present value at the refinancing stage, but one that is higher than that of competing portfolio projects. Our article may help understand provisions used in venture capital finance that limit a fund's initial capital and make it difficult to add more capital once the initial venture capital fund is raised.]

[We examine the theoretical predictions that link acquirer returns to diversity of opinion and information asymmetry. Theory suggests that acquirer abnormal returns should be negatively related to information asymmetry and diversity-of-opinion proxies for equity offers but not cash offers. We find that this is the case and that, more strikingly, there is no difference in abnormal returns between cash offers for public firms, equity offers for public firms, and equity offers for private firms after controlling for one of these proxies, idiosyncratic volatility.]

[This article uses a unique option data set to provide detailed descriptive statistics on the purchased and written open interest and open buy and sell volume of several classes of investors. We also show that volatility trading through straddles and strangles accounts for a small fraction of option trading volume and presents evidence that a large percentage of call writing is part of covered call positions. Finally, we find that during the stock market bubble of the late 1990s and early 2000 the least sophisticated investors in the data set substantially increased their purchases of calls on growth but not value stocks.]

We develop an agency model of financial contracting. We derive long-term debt, a line of credit, and equity as optimal securities, capturing the debt coupon and maturity; the interest rate and limits on the credit line; inside versus outside equity; dividend policy; and capital structure dynamics. The optimal debt-equity ratio is history dependent, but debt and credit line terms are independent of the amount financed and, in some cases, the severity of the agency problem. In our model, the agent can divert cash flows; we also consider settings in which the agent undertakes hidden effort, or can control cash flow risk.

Agency problems limit firms' access to capital markets, curbing investment. Firms and investors seek contractual ways to mitigate these problems. What are the implications for investment? We present a theory of a firm's investment dynamics in the presence of agency problems and optimal long-term financial contracts. We derive results relating firms' investment decisions, current and past cash flows, firm size, capital structure, and dividends. Among the results, optimal investment is increasing in current and past cash flow; and optimal investment is positively serially correlated over time (after controlling for investment opportunities). These results hold for a range of agency problems.