Quantity precommitment, Cournot outcome and asymmetric capacity costs

This note extends Kreps and Scheinkman's result -showing that a production capacity choice stage followed by price competition yields the same outcome as a Cournot game- to a setting where capacity costs are asymmetric.capacity, Bertrand competition, Kreps-Scheinkman, asymmetric costs.

A note on quantity precommitment, cournot outcome and asymmetric capacity costs

This paper extends Kreps and Scheinkman's 1983 result, which shows that a production capacity choice stage followed by price competition yields the same outcome as a Cournot game, to a setting where capacity costs are asymmetric.Asymmetric costs

When cost improvements harm consumers

This paper demonstrates that in a vertical structure, improving cost efficiency might sometimes be detrimental to consumers, by increasing market price. This is in stark contrast to the standard result in oligopoly theory which suggests that the surplus generated by any efficiency gain in production is shared between firms and final consumers, depending on the degree of market power. These results are applied in contexts such as international trade, diffusion of knowledge and techniques, and government intervention through income support programs.oligopsonists, retail, vertical structure, cost pass-through.

A model of airport slot allocation with posted prices

In this paper, we study the impact of the introduction of posted prices in the slot allocation process currently in use at congested airports in most European countries. In particular, we show that if the airport is initially saturated, while low level of slot prices entail no response from the airlines, requests for slots ”suddenly and violently” drop when the price reaches a certain threshold. In general, there is therefore no market clearing price for airport slots. We also present a dynamic model which highlights how the current grandfather rule - stating that slots used today are kept in the future - generates baby-sitting, that is airlines requiring and using slots today just because they expect them to be profitable in the future.Capacity-constrained competition, airport slots

Auctioning airport slots (?)

The current allocation of slots on congested European airports constitutes an obstacle to the effective liberalisation of air transportation undertaken in Europe. With a view to favouring efficient slot utilisation and competition, as is the goal of the European commission, we propose to use a market mechanism, based on temporary utilisation licences. In order to allocate those licences, we propose and describe an iterated combinatorial auction mechanism where a percentage of licences would be reallocated each season. A secondary market would also be set up in order to reallocate slots during a season. Since a combinatorial auction involve a complex optimisation procedure, we describe how it can be made to work in the case of auctions.slots; airports; licence; auction; combinatorial

Optimal Auctions when a seller is bound to sell to collusive bidders (new version of "using lotteries ...")

I consider optimal auctions for a seller who is bound to sell a single item to one of two potential buyers, organized in a `well-coordinated' cartel. I show that, even though the seller cannot deter collusion, he can optimally accommodate it by employing a simple mechanism which imposes an inefficient allocation on the bidders unless they pay a sufficiently high amount to avoid it.auctions; optimal auctions; collusion; cartel; mechanism design; auction theory

Using lotteries in auctions when buyers collude

This paper studies the optimal auction for a seller who is bound to sell a single item to one of two potential buyers organized in a ”well-coordinated” cartel. After discussing the way the cartel reacts to any auction mechanism, we show that if the seller has no way to deter collusion, he can still accomodate it optimally with a very simple mechanism, either having the cartel pay to get an efficient allocation or randomly allocating the item. We then discuss the way to implement this mechanism, so that it enables a fair amount of competition if the seller made a mistake and the buyers don’t collude. We find that a simple implementation using reserve prices and lotteries may yield expected revenues close to the optimum if buyers compete, while highly increasing expected revenues if they collude. Finally, we discuss the extension to the n-buyers case.auctions; optimal auctions; collusion; cartel; mechanism design; auction theory

Traitement biologique des effluents de serre par des marais filtrants artificiels et des bioréacteurs passifs

Lors de l'irrigation des cultures de tomate produites en serre, une partie importante de l'eau enrichie en engrais est rejetée dans l'environnement afin de contrôler la conductivité électrique du milieu de culture et l'équilibre ionique de la solution du sol. Plusieurs contraintes limitent la réutilisation de cette eau, par exemple une surcharge de l'eau en ions sulfates (SO₄²⁻) et la présence d'agents pathogènes, comme Pythium ultimum ou Fusarium oxysporum. Les objectifs de cette recherche étaient de (1) réduire les SO₄²⁻ en présence d'ions nitrates (NO₃⁻), (2) éliminer les agents pathogènes P. ultimum et F. oxysporum présents dans l'effluent de serre, (3) évaluer l'effet suppresseur de ces eaux traitées envers la pourriture pythienne, (4) comparer la croissance de plants de tomate irrigués avec les eaux traitées par les marais, (5) comprendre l'effet de différents amendements de C dans les marais filtrants sur la diversité métabolique et phylogénétique des populations microbiennes, et finalement (6) évaluer la capacité de bioréacteurs passifs à réduire les SO₄²⁻en présence d'ions NO₃⁻ , et à éliminer les agents pathogènes P. ultimum et F. oxysporum. Nos résultats ont démontré l'importance de la quantité et de la qualité de la source exogène de carbone (C) pour réduire les ions NO₃⁻ et SO₄²⁻. Pour un enlèvement optimal de SO₄²⁻et de NO₃⁻ (99 %), l'apport de C exogène doit atteindre les seuils C :N = 3,4 et COD: SO₄²⁻= 0,36. D'autre part, les marais filtrants ont été performants (99,99 %) à réduire les agents pathogènes P. ultimum et F. oxysporum, notamment par l'adsorption de ceux-ci au biofilm formé et par la production d'enzymes extracellulaires par les microorganismes. Le traitement des effluents par les marais confère également à l'eau des propriétés suppressives envers la pourriture pythienne. La quantité et la qualité du contenu en carbone utilisé pour amender les AWs ont eu une forte incidence sur l'activité métabolique des microorganismes pour l'utilisation des sources de N, P et S. Finalement, l'utilisation de bioréacteurs passifs a montré, par une activité microbienne importante, une efficacité similaire aux marais filtrants pour réduire les ions sulfates en présence de nitrates. De plus, les bioréacteurs passifs ont été aussi performants que les marais pour éliminer les agents pathogènes étudiés. L'utilisation des marais filtrants et des bioréacteurs constitue une alternative durable pour le traitement des effluents de serre

Intelligent Vehicle embedded sensors fault detection and identification using analytical redundancy and non-linear transformations

This work proposes a fault detection architecture for a vehicle embedded sensors, allowing to deal with both system non-linearity and environmental disturbances and degradations. The proposed method use measurements analytical redundancy and a non-linear transformation to generate the residual value allowing the fault detection. A strategy dedicated to the optimization of the detection parameters choice is also develope