Empirical research on cities starts with a spatial equilibrium condition: workers and firms are assumed to be indifferent across space. This condition implies that research on cities is different from research on countries, and that work on places within countries needs to consider population, income, and housing prices simultaneously. Housing supply elasticity will determine whether urban success reveals itself in the form of more people or higher incomes. Urban economists generally accept the existence of agglomeration economies, which exist when productivity rises with density, but estimating the magnitude of those economies is difficult. Some manufacturing firms cluster to reduce the costs of moving goods, but this force no longer appears to be important in driving urban success. Instead, modern cities are far more dependent on the role that density can play in speeding the flow of ideas. Finally, urban economics has some insights to offer related topics such as growth theory, national income accounts, public economics, and housing prices.

We study a principal's choice to centralize or delegate decisions to an agent when delegation can be used to encourage the agent to communicate potential problems. We find that the principal may choose centralization either to exercise better control over the agent's actions or to provide stronger incentives. Delegation emerges in equilibrium only if the costs of effort to acquire information for both the principal and the agent are sufficiently high. We find that increases in the principal's penalties for an incorrect decision may increase the principal's expected payoff, owing to optimal organizational responses. In addition, catastrophic risk, the risk of incorrectly accepting a defective audit (or product), may be greater under centralization than under delegation. Furthermore, catastrophic risk can be increased by well‐intentioned legislative efforts to decrease such risk by, for example, increasing the agent's penalties for failing to take a corrective action, because the organizational structure may change.

We analyze the desirability of level playing fields in international financial regulation. In general, level playing fields impose the standards of the weakest regulator upon the best-regulated economies. However, they may be desirable when capital is mobile because they counter a cherry-picking effect that lowers the size and efficiency of banks in weaker economies. Hence, while a laissez faire policy favors the better-regulated economy, level playing fields are good for weaker regulators. We show that multinational banking mitigates the cherry-picking effect, and reduces the damage that a level playing field causes in the better-regulated economy.

Explanations for Africa's poor long-run growth performance have varied over time. The theories examined include geography (Jeffrey D. Sachs and Andrew Warner 1997); institu tions (William Easterly and Ross Levine 1997;

Previous empirical studies on the “rationality” of economic and financial forecasts generally test for generic properties such as bias or autocorrelated errors but provide only limited insight into the behavior behind inefficient forecasts. This paper tests for a specific form of forecast bias. In particular, we examine whether expert consensus forecasts of monthly economic releases are systematically biased toward the value of previous months’ releases. Such a bias would be consistent with the anchoring and adjustment heuristic described by Tversky and Kahneman (1974) or could arise from professional forecasters’ strategic incentives. We find broad-based and significant evidence for this form of bias, which in some cases results in sizable predictable forecast errors. To investigate whether market participants’ expectations are influenced by this bias, we examine interest rate reactions to economic news. We find that bond yields react only to the residual, or unpredictable, component of the forecast error and not to the component induced by anchoring, suggesting that expectations of market participants anticipate this bias embedded in expert forecasts.

Survey evidence indicates widely held managerial beliefs that earnings volatility is negatively related to earnings predictability. In addition, existing research suggests that earnings volatility is determined by economic and accounting factors, and both of these factors reduce earnings predictability. We find that the consideration of earnings volatility brings substantial improvements in the prediction of both short- and long-term earnings. Conditioning on volatility information also allows one to identify systematic errors in analyst forecasts, which implies that analysts do not fully understand the implications of earnings volatility for earnings predictability.

Consumers may overestimate the precision of their demand forecasts. This overconfidence creates an incentive for both monopolists and competitive firms to offer tariffs with included quantities at zero marginal cost, followed by steep marginal charges. This matches observed cellular phone service pricing plans in the United States and elsewhere. An alternative explanation with common priors can be ruled out in favor of overconfidence based on observed customer usage patterns for a major US cellular phone service provider. The model can be reinterpreted to explain the use of flat rates and late fees in rental markets, and teaser rates on loans. Nevertheless, firms may benefit from consumers losing their overconfidence.

Arthur Andersen’s reputation was tarnished following news that its Houston office had shredded documents related to the auditing of energy giant Enron. Earlier studies documented widespread spillover of the reputation effect, suggesting a strong commonality in Big 5 audit practices. We examine whether the market is more discriminating in its assessments. We focus on the roles industry specialization of auditors and the geography of clients’ audit offices play in accounting for the contagion. Our results are supportive of investors who differentiate audit practices by industry and who account for the location of the specific office where the audit work is done. We find that losses suffered by energy firms or firms located close to Houston are equivalent to approximately 90% of the aggregate abnormal losses suffered by Big 5 clients. Our evidence suggests the possibility of more localized impact of accounting scandals and supports accounting regulations targeted at individual industries.

Much attention has been devoted to understanding and modeling the dynamics of implied volatility curves and surfaces. This is crucial for both trading, pricing and risk management of option positions. We suggest a simple, yet flexible, model, based on a discrete and linear Kalman filter updating of the volatility skew. From a risk management perspective, we assess whether this model is capable of producing good density forecasts of daily returns on a number of option portfolios. We also compare our model to the sticky-delta and the vega–gamma alternatives. We find that it clearly outperforms both alternatives, given its ability to easily account for movements of different nature in the volatility curve.