Rumors

A Kyle (1985) model with private information diffusion is used to examine the motivation to spread stock tips. An informed investor with limited investment capacity spreads imprecise rumors to an audience of followers. Followers trade on the advice and move the price. Due to the imprecision of the rumor, the price overshoots with positive probability. This gives the rumormonger the opportunity to trade twice: First when she receives information, then when she knows the price to be overshooting. In equilibrium, rumors are informative and both rumormongers and followers increase their profits at the expense of uninformed liquidity traders.     

Changing rewards in contests: Has the three-point rule brought more offense to soccer?

In the mid-nineties FIFA decided to increase from two to three the number of points assigned to the winning team of a soccer match played under traditional round-robin national leagues. Since a game of soccer can be regarded as a contest, FIFA's measure provides an interesting case-study for analysing how a change in the system of rewards (from a zero to a non-zero sum rule) may affect the contestants' equilibrium behaviour. In this paper we try to assess, both theoretically and empirically, whether FIFA's new point rule has changed soccer towards a more offensive game, in which teams adopt more risky strategies. In particular, we evaluate the “na?ve hypothesis” according to which the measure would induce every team to play always more offensively, and we explore the extent to which the change in teams' behaviour may be affected by quality differentials between teams. Our most important hypothesis is that when the asymmetry between opposing teams is large enough, an increase in the reward for victory induces the weaker team to play more defensively, rather than the opposite. By looking at a subset of matches held in the Portuguese first division league, which approximate the conditions of our model, we find support for this hypothesis. First version received: July 1999/Final version received: May 2001     

Does self-regulation work? Experimental evidence of the reputational incentives of Self-Regulatory Organizations

Self-regulation (SR) is a common way of enforcing quality in markets (such as banking, financial services and several professions) and in a variety of public and private organizations. We provide experimental evidence of the reputational incentives of self-regulatory organizations (SROs) to publicly disclose versus cover-up fraud in an incomplete information environment. We find that observed behaviour is generally consistent with Bayesian equilibrium when subjects are informed about the relative likelihood of fraud detection by a ‘vigilant’ versus a ‘lax’ SRO type. In particular, a fraud disclosure equilibrium is supported when subjects are informed that the ‘vigilant’ SRO is more likely to detect fraud; otherwise, a cover-up equilibrium is supported. However, when subjects are not informed about the relative likelihood of fraud detection by the SRO types (as expected in real SR situations), no equilibrium is strongly supported. Our results suggest that in practice, the reputation-based incentives for effective SR may be inherently ambiguous and weak.     

Conditional ordering extensions

We produce a solution to the problem of extending a quasiordering conditional on a finite list of ex-ante comparisons between pairs. This constitutes yet another extension of the classical Szpilrajn’s theorem. Some examples of use of our result follow.     

Short-term asymptotics for the implied volatility skew under a stochastic volatility model with Lévy jumps

The implied volatility skew has received relatively little attention in the literature on short-term asymptotics for financial models with jumps, despite its importance in model selection and calibration. We rectify this by providing high order asymptotic expansions for the at-the-money implied volatility skew, under a rich class of stochastic volatility models with independent stable-like jumps of infinite variation. The case of a pure-jump stable-like Lévy model is also considered under the minimal possible conditions for the resulting expansion to be well defined. Unlike recent results for “near-the-money” option prices and implied volatility, the results herein aid in understanding how the implied volatility smile near expiry is affected by important features of the continuous component, such as the leverage and vol-of-vol parameters. As intermediary results, we obtain high order expansions for at-the-money digital call option prices, which furthermore allow us to infer analogous results for the delta of at-the-money options. Simulation results indicate that our asymptotic expansions give good fits for options with maturities up to one month, underpinning their relevance in practical applications, and an analysis of the implied volatility skew in recent S&P 500 options data shows it to be consistent with the infinite variation jump component of our models.     

Environmental Policy Instruments: Technology Adoption Incentives with Imperfect Compliance

We study the incentives to adopt advanced abatement technologies in the presence of imperfect compliance. Interestingly, incentives under emission taxes and pollution abatement subsidies are the same that in the perfect compliance scenario. However, under emission standards imperfect compliance can increase firms’ incentives to invest, whereas under an emission permit mechanism investment incentives decrease only if widespread non-compliance induces a reduction in the permit price. Our results are valid for fairly general characteristics of the monitoring and enforcement strategies commonly found in both, theoretical and empirical applications.     

The effects of macroeconomic stability on foreign trade. An analysis for Spain, 1986–2000

Two main factors underlie the rebirth of interest in the study of the influence of the real exchange rate on trade, the reduction of its volatility and the current trend towards price stability. The objective of this study is to analyse the effects of the process of nominal convergence, required of the European member states for the fulfilment of monetary integration, on foreign trade flows. The case of Spain, which is especially interesting in this context, is studied for the period 1986 to 2000. The results of estimating the aggregate functions of the export and import of goods shows how macroeconomic stability has altered the behaviour of trade with respect to the two basic determinants – income and prices – how it has caused a significant structural change in the real exchange rate and, finally, how it has laid the explanatory bases for transactions in the twenty-first century with the single currency – the euro.     

Sector-specific capital, “Bang-bang” investment,and the Filippov solution

Bang-bang investment in a two-sector growth model with immobile capital is rational and leads to a unique and globally stable long-run equilibrium along a sliding trajectory. This steady state coincides with the stationary equilibrium in the traditional model with non-sector-specific capital.This article was written while the authors were visiting scholars at Cornell University. We gratefully acknowledge financial assistance from the Erasmus University Trust Fund and the Netherlands Scientific Organization. We would like to thank, without implicating, two anonymous referees, Martijn Herrmann, Jean-Marie Viaene, Claus Weddepohl, and the participants of seminars at the University of Maryland, the University of Montreal, and Erasmus University Rotterdam for perceptive remarks and useful comments. Jeroen Hinloopen and Rien Wagenvoort provided able graphical assistance. The views expressed in this article are those of the authors and not necessarily those of the World Bank.     

What circumstances lead a government to promote brain drain?

This paper aims to complement the existing theoretical brain drain literature, focusing on the interaction between education, skilled emigration and government intervention in a small open economy. This article first characterises different emigration patterns that may arise in equilibrium, then seeks the conditions that lead a government to promote brain-drain. The model shows that the government may promote skilled emigration among workers with intermediate skills even though the resulting brain drain decreases per capita income. Emigrants remittances outweigh the income they would produce if they did not emigrate. Therefore, the government makes less severe the fall in per capita income that follows the brain drain by encouraging emigration among those skilled workers who are more productive abroad.     

Farmland for tomorrow in densely populated areas

The paper describes the results of a research that aimed to come up with a well structured method to estimate future farmland requirements in densely populated areas. By using in depth interviews, scenario analysis and strategic orientation rounds, a method is developed to support policy optimization and to explore alternative future developments. The method is applied to the case of agriculture in the Flemish part of Belgium to show the feasibility of the model and to provide input for the discussion among policy makers in Flanders. The research results can be used by policy makers to build a new Spatial Plan Flanders for the period 2007–2013.