We review the theory and evidence on IPO activity: why firms go public, why they reward first-day investors with considerable underpricing, and how IPOs perform in the long run. Our perspective is threefold: First, we believe that many IPO phenomena are not stationary. Second, we believe research into share allocation issues is the most promising area of research in IPOs at the moment. Third, we argue that asymmetric information is not the primary driver of many IPO phenomena.

We explore behavioral explanations for sub-optimal corporate investment decisions. Focusing on the sensitivity of investment to cash flow, we argue that personal characteristics of chief executive officers, in particular overconfidence, can account for this widespread and persistent investment distortion. Overconfident CEOs overestimate the quality of their investment projects and view external finance as unduly costly. As a result, they invest more when they have internal funds at their disposal. We test the overconfidence hypothesis, using data on personal portfolio and corporate investment decisions of CEOs in Forbes 500 companies. We classify CEOs as overconfident if they repeatedly fail to exercise options that are highly in the money, or if they habitually acquire stock of their own company. The main result is that investment is significantly more responsive to cash flow if the CEO displays overconfidence. In addition, we identify personal characteristics other than overconfidence (education, employment background, cohort, military service, and status in the company) that strongly affect the correlation between investment and cash flow. We are indebted to Brian Hall and David Yermack for providing us with the data. We are very grateful to Jeremy Stein for his invaluable support and comments. We also would like to thank Philippe Aghion, George

Does CEO overconfidence help to explain merger decisions? Overconfident CEOs overestimate their ability to generate returns. As a result, they overpay for target companies and undertake value-destroying mergers. The effects are strongest if they have access to internal financing. We test these predictions using two proxies for overconfidence: CEOs' personal overinvestment in their company and their press portrayal. We find that the odds of making an acquisition are 65 % higher if the CEO is classified as overconfident. The effect is largest if the merger is diversifying and does not require external financing. The market reaction at merger announcement (–90 basis points) is significantly more negative than for non-overconfident CEOs (–12 basis points). We consider alternative interpretations including inside information, signaling, and risk tolerance.

∗This paper is an updated version of a previous working paper, “The Positive Role of Overconfidence and

Incorporating preference for social status into a simple model of portfolio choice helps to explain a range of qualitative and quantitative stylized facts about the heterogeneity in asset holdings among U.S. households. I specify preferences for status parsimoniously as a function of a household’s wealth relative to aggregate wealth. In the model, investors hold concentrated portfolios, suggesting, in particular, a possible explanation for the apparently small premium for undiversified entrepreneurial risk. Consistent with empirical evidence, the wealthier households own a disproportionate share of risky assets, particularly private equity, and experience more volatile consumption growth. The model is calibrated to match the empirical level of risky asset holdings without generating excessive volatility of consumption growth and crosssectional wealth mobility. I am grateful to John Cochrane, John Heaton, Tobias Moskowitz, and Pietro Veronesi for their advice

Key Words: venture capital, cost of capital, diversification We use a database of recent high-technology IPOs to estimate opportunity cost of capital for venture capital investors and entrepreneurs. Entrepreneurs face the risk-return tradeoff of the CAPM as the opportunity cost of holding a portfolio that necessarily is underdiversified. We model the entrepreneur’s opportunity cost by assuming the venture financial claim and a market index comprise the entrepreneur’s portfolio. We estimate total risk and correlation with the market and examine how these estimates and opportunity cost of capital vary with underdiversification and by industry and financial maturity of earlystage firms. Early-stage firms have market risk levels similar to more established firms in our sample, but have higher total risk. Equity of newly public, high tech firms generally is more than five times as risky as the market and correlations with the market generally are below 0.2 so that beta is close to one. Assuming reasonable levels of underdiversification in the entrepreneur’s portfolio and a one-year holding period, depending on industry and stage of development, the entrepreneur’s opportunity cost generally is two to four times as high as that of a well-diversified investor. With a 4.0 percent risk-free rate and 6.0 percent market risk premium, for the sample average observation, the cost of capital of a well-diversified investor is estimated to be 11.4 percent, or 16.7 percent before the management fees and carried interest

A risk-averse manager’s overconfidence makes him less conservative. As a result, it is cheaper for firms to motivate him to pursue valuable risky projects. When compensation endogenously adjusts to reflect outside opportunities, moderate levels of overconfidence lead firms to offer the manager flatter compensation contracts that make him better off. Overconfident managers are also more attractive to firms than their rational counterparts because overconfidence commits them to exert effort to learn about projects. Still, too much overconfidence is detrimental to the manager since it leads him to accept highly convex compensation contracts that expose him to excessive risk. AVAST EXPERIMENTAL LITERATURE finds that individuals are usually overconfident in that they believe their knowledge to be more precise than it actually is. The incidence of overconfidence is likely to be even greater among CEOs than among individuals at large; for example, Goel and Thakor (2008) show that overconfident individuals are more likely to win the intrafirm tournaments that lead to the rank of CEO. Since overconfidence directly influences decision-making, it is logical to investigate the effects that overconfident managers have on corporate policies and firm value. How does overconfidence affect the investment decisions that managers make on behalf of shareholders? How do compensation contracts optimally adjust to these effects? Do firms benefit from managerial overconfidence? Can overconfidence ever benefit the biased

Excess entry refers to the high failure rate of new entrepreneurial ventures. Economic explanations suggest “hit and run ” entrants and risk-seeking behavior. A psychological explanation is that people (entrepreneurs) are overconfident in their abilities (Camerer & Lovallo, 1999). Characterizing entry decisions as ambiguous gambles, we alternatively suggest – following Heath and Tversky (1991) – that people seek ambiguity when the source of uncertainty is related to their competence. Overconfidence, as such, plays no role. This hypothesis is confirmed in an experimental study that also documents the phenomenon of reference group neglect. Finally, we emphasize the utility that people gain from engaging in activities that contribute to a sense of competence. This is an important force in economic activity that deserves more explicit attention.

I provide a synthesis of the Behavioural finance literature over the past two decades. I review the literature in three parts, namely, (i) empirical and theoretical analyses of patterns in the cross-section of average stock returns, (ii) studies on trading activity, and (iii) research in corporate finance. Behavioural finance is an exciting new field because it presents a number of normative implications for both individual investors and CEOs. The papers reviewed here allow us to learn more about these specific implications.

Communities facing serious and repetitive risks from natural hazards often fail to protect themselves leaving the Federal government to pay for recovery. By integrating insights from cognitive psychology into a game theoretic model of sequential choice, this paper o#ers a positive account of social choice about catastrophic risks. Empirical work suggests individuals exhibit an availability bias and over-optimism in their evaluation of disaster risks. Moreover, surveys indicate that individuals often rely on publicly observable actions as information gathering mechanisms, making informational cascade models particularly relevant. This paper uses a basic formal model to clarify the impact of individual cognitive biases on social outcomes. The formal model demonstrates that bias can, but does not always spread through a group, potentially a#ecting the propensity of communities to herd around sub-optimal strategies. The proportion of biased actors in the group, the magnitude of the bias, and the location of the biased individual in the choice sequence all determine the impact of bias on social decisions about risk management. Cascades and Catastrophic Risk 1 1