Markov-perfect Nash equilibria in a class of resource games

Summary. A general model of non-cooperating agents exploiting a renewable resource is considered. Assuming that the resource is sufficiently productive we prove that there exists a continuum of Markov-perfect Nash equilibria (MPNE). Although these equilibria lead to over-exploitation one can approximate the efficient solution by MPNE both in the state space and the payoff space. Furthermore, we derive a necessary and sufficient condition for maximal exploitation of the resource to qualify as a MPNE. This condition is satisfied if there are sufficiently many players, or if the players are sufficiently impatient, or if the capacity of each player is sufficiently high.Received: November 1, 1996This revised version was published online in February 2005 with corrections to the cover date.     

Food costs for the current and recommended diet of German infants,children and adolescents

Abstract Higher food costs of a recommended diet may be a barrier to the improvement of unhealthy dietary habits. For the assessment of food costs for children, age-specific dietary intakes as well as average food prices must be known. This study is based on the measured food intake from a total of 1668 3-day weighed diet records of children aged from 5 months to 18 years and on recommended dietary intakes for these age groups. Based on the food costs related to the energy intake (Deutschmarks per megajoule; DM per MJ), the recommended diet using common food products does not incur higher costs than the current diet in all age groups. For infants, a diet using commercial infant food conforming to the restrictive German pesticide regulations incurs 50–150% higher food costs than the use of home-made meals. For children and adolescents, the nutritionally inferior quality of the current diet can be improved by a price-balanced interchange of foods, mainly by favouring plant foods instead of meat and confectionery.     

Non‐linear Dynamics in the Infinite Time Horizon Model

Using results from the theory of non‐linear dynamical systems, it has been shown that optimal growth theory can provide new explanations for business cycles and for international differences in growth and development. The present survey concentrates on this aspect of optimal growth theory, that is on the possibility of fluctuations and non‐uniqueness in models of optimal capital accumulation. It is a selective survey on non‐linear dynamics in infinite time horizon models of optimal growth.     

Wealth and Income Inequality in Europe

While it has long been apparent that global levels of wealth and income inequality have been steadily increasing since the 1970s, the issue received scant attention in Europe until the recent fi nancial crisis and the resulting Great Recession illuminated for the general public just how great the chasm between the very rich and everybody else had grown. This realisation was coupled with an increased focus on inequality among economists and other academics, leading to a fresh drive for policy ideas to remedy the alarming trend. This Forum comprises a diverse range of viewpoints on the recent history and dynamics of inequality within Europe, each striving to defi ne the root causes in the various countries being examined. The defi nition of these causes, of course, can inform the direction of policies aimed at alleviating the growing inequality in many European countries and thereby curtail one of the major political and social issues of our time.     

Perceptions regarding strategic and structural entry barriers

This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on the seven generic factors, a conjoint analysis is carried out to identify the most important factors perceived by firms. The conjoint analysis shows that in particular the barriers rooted in three underlying dimensions require attention of market authorities as they may prevent new entrants from entry: capital, access to distribution channels and strategic action. Remarkably, government rules and regulations, product differentiation, research and development (R&D) and advertising constitute minor entry problems according to firms.     

Policy rule Nash equilibria

Abstract.  We study how different types of instrument rules affect the outcome of a monetary policy game between the central bank and the private sector. Policy rules can be independent of output and a shock, functions of the shock, or functions of output. We rank the Nash equilibria generated by different types of policy rules according to the central bank's ex ante expected loss. If both players can condition on output, then the following is true: no equilibrium exists if the central bank cares much about output stability and little about price stability, and infinitely many equilibria exist otherwise. JEL classification: E52, E61
Equilibres à la Nash des règles de politique.  L'auteur étudie comment le choix de divers types de règles instrumentales a un effet sur le résultat d'un jeu de politique monétaire entre la banque centrale et le secteur privé. Les règles de politique peuvent être indépendantes de la production ou d'un choc, être fonction d'un choc ou de la production. On établit un ordre des équilibres à la Nash engendrés par ces divers types de règles de politique selon la taille des pertes anticipées ex ante par la banque centrale. Si les deux joueurs fondent leur comportement sur la production, il s'ensuit que — aucun équilibre n'existe si la banque centrale est très préoccupée par la stabilité du niveau de production et peu préoccupée de la stabilité des prix, et autrement, une infinité d'équilibres existent.