This article surveys research on corporate governance, with special attention to the importance of legal protection of investors and of ownership concentration in corporate governance systems around the world.

Textbook arbitrage in financial markets requires no capital and entails no risk. In reality, almost all arbitrage requires capital and is typically risky. Moreover, professional arbitrage is conducted by a relatively small number of highly specialized investors using other people's capital. Such professional arbitrage has a number of interesting implications for security pricing, including the possibility that arbitrage becomes ineffective in extreme circumstances when prices diverge far from fundamental values. The model also suggests where anomalies in financial markets are likely to appear, and why arbitrage fails to eliminate them.

The authors explore the determinants of liquidation values of assets, particularly focusing on the potential buyers of assets. When a firm in financial distress needs to sell assets, its industry peers are likely to be experiencing problems themselves, leading to asset sales at prices below value in best use. Such illiquidity makes assets cheap in bad times and so ex ante is a significant private cost of leverage. The authors use this focus on asset buyers to explain variation in debt capacity across industries and over the business cycle, as well as the rise in U.S. corporate leverage in the 1980s.

In the presence of aggregate demand spillovers, an imperfectly competitive form's profit is positively related to aggregate income, which in turn rises with profits of all firms in the economy. This pecuniary externality makes a dollar of a firm's profit raise aggregate income by more than a dollar since other firms' profits also rise, and in this way gives rise to a "multiplier." Since such multipliers are ignored by firms making investment decisions, privately optimal investment decisions under uncertainty will not in general be socially optimal. Under reasonable conditions, investment is too low.

In a corporation with many small owners, it may not pay any one of them to monitor the performance of the management. We explore a model in which the presence of a large minority shareholder provides a partial solution to this free-rider problem. The model sheds light on the following questions: Under what circumstances will we observe a tender offer as opposed to a proxy fight or an internal management shake-up? How strong are the forces pushing toward increasing concentration of ownership of a diffusely held firm? Why do corporate and personal investors commonly hold stock in the same firm, despite their disparate tax preferences?

We propose a theory of financial intermediaries operating in markets influenced by investor sentiment. In our model, banks make, securitize, distribute, and trade loans, or they hold cash. They also borrow money, using their security holdings as collateral. Banks maximize profits, and there are no conflicts of interest between bank shareholders and creditors. The theory predicts that bank credit and real investment will be volatile when market prices of loans are volatile, but it also points to the instability of banks, especially leveraged banks, participating in markets. Profit-maximizing behavior by banks creates systemic risk.

We present a model of mergers and acquisitions based on stock market misvaluations of the combining firms. The key ingredients of the model are the relative valuations of the merging firms and the market's perception of the synergies from the combination. The model explains who acquires whom, the choice of the medium of payment, the valuation consequences of mergers, and merger waves. The model is consistent with available empirical findings about characteristics and returns of merging firms, and yields new predictions as well.

We describe how managers can entrench themselves by making manager-specific investments that make it costly for shareholders to replace them. By making manager-specific investments, managers can reduce the probability of being replaced extract higher wages and larger perquisites from shareholders, and obtain more latitude in determining corporate strategy. Our model of entrenchment has empirical implications that are consistent with the evidence on managerial behavior.