Managements (“insiders”) of many corporations, especially small or newly-public firms, invest considerable resources in investor relations. We develop a model to explore the incentives of insiders to undertake such costly investments. We point out that insiders may undertake such investments not necessarily to improve the share price, but to enhance the liquidity of their block of shares. This leads to a divergence of interest between insiders and dispersed outside shareholders regarding investor relations. Our model predicts that the demographics of insiders (e.g. liquidity needs, size of equity stakes) are important determinants of the extent of investor relations across firms.

We infer the latent social networks of investors using data on their stock holdings. We map linkages to portfolio weights using a portfolio-choice model. The precision of an investor’s private signal about firm value is assumed to increase with his connections in the city where the firm is headquartered. Using money-manager data, we find that managerial linkages to a city are overly dispersed relative to the Erdös–Rényi model of i.i.d. connections. Managers at the tail of this distribution with non-i.i.d. linkages have more university alumni in that city. Their stock holdings there outperform their holdings in other cities.

Motivated by the recent subprime mortgage crisis, we explore whether speculative bubble models of equity based on investor disagreement and short-sales constraints can also provide an explanation for the overvaluation of debt contracts. We find that this is unlikely. Equity bubbles are loud: price and volume go together as investors speculate on capital gains from reselling to more optimistic investors. But this resale option is limited for debt since its upside payoff is bounded. Debt bubbles then require an optimism bias among investors. But greater optimism leads to less speculative trading as investors view the debt as safe and having limited upside. Debt bubbles are hence quiet—high price comes with low volume. We find the predicted price–volume relationship of credits over the 2003–2007 credit boom.

We develop a theory of market crashes based on differences of opinion among investors. Because of short-sales constraints, bearish investors do not initially participate in the market and their information is not revealed in prices. However, if other previously bullish investors bail out of the market, the originally bearish group may become the marginal “support buyers,” and more will be learned about their signals. Thus accumulated hidden information comes out during market declines. The model explains a variety of stylized facts about crashes and also makes a distinctive new prediction—that returns will be more negatively skewed conditional on high trading volume.

Households hold undiversified stock portfolios of firms headquartered near their city of residence. Leading explanations assign a causal role for proximity. The literature neglects that distance is endogenous. Households may locate based on unobservables such as optimism about a city’s economic prospects, which can be correlated with latent local-stock demand. We use location-choice models to account for this selection. We propose as instruments that older households prefer to locate in recreational areas for non-pecuniary reasons. Our analysis based on a widely used household data set yields significantly smaller estimates for proximity in determining portfolio choice compared to those in the literature.

We investigate whether the returns of industry portfolios predict stock market movements. In the US, a significant number of industry returns, including retail, services, commercial real estate, metal, and petroleum, forecast the stock market by up to two months. Moreover, the propensity of an industry to predict the market is correlated with its propensity to forecast various indicators of economic activity. The eight largest non-US stock markets show remarkably similar patterns. These findings suggest that stock markets react with a delay to information contained in industry returns about their fundamentals and that information diffuses only gradually across markets.

We test the hypothesis that arbitrageurs amplify economic shocks in equity markets. The ability of speculators to hold short positions depends on asset values. Shorts are often reduced following good news about a stock. Therefore, the prices of highly shorted stocks are excessively sensitive to shocks compared with stocks with little short interest. We confirm this hypothesis using several empirical strategies including two quasi-experiments. In particular, we establish that the price of highly shorted stocks overshoots after good earnings news due to short covering compared with other stocks.

We examine security analysts' career concerns by relating their earnings forecasts to job separations. Relatively accurate forecasters are more likely to experience favorable career outcomes like moving up to a high‐status brokerage house. Controlling for accuracy, analysts who are optimistic relative to the consensus are more likely to experience favorable job separations. For analysts who cover stocks underwritten by their houses, job separations depend less on accuracy and more on optimism. Job separations were less sensitive to accuracy and more sensitive to optimism during the recent stock market mania. Brokerage houses apparently reward optimistic analysts who promote stocks.

ABSTRACT We model a market populated by two groups of boundedly rational agents: “newswatchers” and “momentum traders.” Each newswatcher observes some private information, but fails to extract other newswatchers' information from prices. If information diffuses gradually across the population, prices underreact in the short run. The underreaction means that the momentum traders can profit by trend‐chasing. However, if they can only implement simple (i.e., univariate) strategies, their attempts at arbitrage must inevitably lead to overreaction at long horizons. In addition to providing a unified account of under‐ and overreactions, the model generates several other distinctive implications.

ABSTRACT The risk and return trade‐off, the cornerstone of modern asset pricing theory, is often of the wrong sign. Our explanation is that high‐beta assets are prone to speculative overpricing. When investors disagree about the stock market's prospects, high‐beta assets are more sensitive to this aggregate disagreement, experience greater divergence of opinion about their payoffs, and are overpriced due to short‐sales constraints. When aggregate disagreement is low, the Security Market Line is upward‐sloping due to risk‐sharing. When it is high, expected returns can actually decrease with beta. We confirm our theory using a measure of disagreement about stock market earnings.