Dynamic duopoly with learning through market experimentation

Summary This paper analyzes how learning behaviors can substantially modify the outcome of competition in an oligopolistic industry facing demand uncertainty. We consider the case of a symmetric duopoly game where firms have imperfect information about market demand and learn through observing the volume of their sales. The main body of the paper consists in showing how market experimentation can explain the existence ofprice-dispersion in an oligopolistic industry. We study this phenomenon and its dynamic evolution in the context of an Hotelling duopoly model; we then extend the analysis to general demand functions and toN-firm oligopolies. We discuss some implications of the public good aspect of information about market demand. We then conclude with a few comments on what happens when the value of information in the oligopolistic industry is negative.We are very grateful to Patrick Bolton for his helpful advice. We also wish to thank Richard Caves, Anthony Creane, Jean-Jacques Laffont, Andreu Mas-Colell, Eric Maskin, Jean-Charles Rochet, Margaret Slade, John Sutton, Jean Tirole, Mike Whinston and an anonymous referee.     

Time-consistent linear taxation and redistribution in an overlapping-generations framework

We study time-consistent labour and capital income linear taxationusing an infinite-horizon overlapping-generations model of asmall open economy. Individuals have different productivitiesand the government intervenes for purely redistributive purposes.The study of time-consistent taxation requires the introductionof borrowing restrictions in the economy. We characterize thetime-consistent solution and consider alternative solutionsbased on a simple tax rule. We demonstrate the existence andthe uniqueness of the time-consistent solution using a log-linearutility function. We provide numerical comparisons between time-consistentand time-inconsistent linear taxation: the importance of beingable to make commitment decreases when the differences betweenindividuals increase.     

Contractual Practice and Land Conflicts: The ‘Plant & Share’ Arrangement in Côte d'Ivoire

This paper tackles the broad issue of agrarian contracts, property rights and conflicts in the context of rural Côte d'Ivoire. Since the beginning of the 2000s, a new type of contractual arrangement has been developing rapidly: the ‘Plant & Share’ contract. Through such a contract, a landowner provides the land to a farmer who develops a perennial tree crop plantation; when production starts, the plantation, the plantation and the land, or the product is shared. The aim of the paper is to discuss the conflictive features of the arrangement. I argue that this contract, in spite of its potential for tensions and conflicts, constitutes an alternative to the much more conflictive land sales that currently dominate extra‐familial land transfers in the country.     

WTO Disciplines on Domestic Support and Market Access in Agri‐Food Supply Chains

Multilateral negotiations on agriculture in the WTO are making very little progress as developed economies are reluctant to bind trade‐distorting domestic support and import tariffs at levels acceptable to developing countries. This paper presents the basic Bagwell–Staiger framework as it relates to agricultural trade negotiations. In its basic version, market access commitments are sufficient to achieve efficient trade agreements. We show that vertical linkages between agricultural goods and processed food commodities may prevent countries to reach an efficient trade agreement. We argue that the features of agricultural supply chains hinder the argument that total discretion over domestic policies is appropriate. Les négociations multilatérales de l'OMC sur l'agriculture progressent très lentement étant donné que les pays développés hésitent à maintenir un soutien interne qui fausse les échanges et des barrières tarifaires à des niveaux acceptables pour les pays en développement. Le présent article traite du modèle Bagwell–Staiger dans le contexte des négociations sur le commerce des produits agricoles. Dans sa version de base, les engagements quant à l'accès au marché sont suffisants pour permettre des échanges commerciaux efficaces. Nous montrons que les liens verticaux entre les produits agricoles et les produits alimentaires transformés peuvent empêcher les pays d'atteindre un accord commercial efficace. Nous soutenons que les caractéristiques des chaînes d'approvisionnement agricole entravent l'argument voulant que l'entière discrétion quant aux politiques intérieures soit appropriée.     

THE CHANGING VOLATILITY OF THE SOUTH AFRICAN ECONOMY

During the last decade economic literature explored the presence of and reasons for what became known as “the great moderation” in the US and other G7 countries. “The great moderation” describes the decrease in economic volatility experienced in many of the G7 countries. This paper finds that in South Africa volatility is also not constant (it even finds that there are autoregressive conditional heteroskedastic effects present) and that volatility also decreased, particularly since 1994. Following the literature, the paper explores several reasons for this decrease and finds that smaller shocks, better monetary policy and improvements in the financial sector that place less liquidity constraints on individuals and allow them to manage their debt better are some of the main reasons for the reduction in the volatility of the South African economy. The literature on the G7 also suggests that better inventory management contributed to the lower volatility. However, this seems not to be true for South Africa.     

LE RENOUVELLEMENT PÉRIODIQUE DES CONTRATS DE CONCESSION: LE CAS DES SERVICES DE L'EAU

RESUME ** :  Le renouvellement régulier des contrats de concession apparaît nécessaire pour bénéficier de concurrence dans certains secteurs, comme l'eau. Nous décrivons les contrats et la règle de renouvellement optimaux dans ce contexte. Ils arbitrent entre les diminutions de coûts, en cas de changement de concessionnaire, et les incitations à investir à long terme du concessionnaire en place. La meilleure information du concessionnaire en place sur des éléments constituant une valeur commune de la concession est importante. Nous montrons que ses conséquences diffèrent fortement du cas des enchères de biens.     

The politics of redistributive social insurance

This paper analyses the political support for a social insurance that includes elements of redistribution when there exists an imperfect private insurance alternative. Individuals differ both in their income and risk. The social insurance is compulsory and charges an income-related contribution with pooling of risks. The private insurance is voluntary and charges a contribution based on individual risks. However due to the adverse selection problem, private insurance companies provide only partial insurance. Adopting a non-expected utility model, we show that there is a general majority support for social insurance and that this support is increasing with risk aversion. We also show that a mixed insurance is politically impossible, regardless of the degree of redistribution of social insurance and the joint distribution of risk and income in the population. Lastly, we analyse how the political support for social insurance is affected by any change in its redistributive component and the possibility of using genetic tests.