Strategic vertical integration without foreclosure

We determine the endogenous degree of vertical integration in a model of successive oligopoly that captures both efficiency gains and strategic effects. We show that vertical merger waves can be expected to stop by themselves before integration is complete. Consequently, vertical foreclosure plays no significant role in this paper that claims for a soft approach of vertical integration by antitrust authorities.merger waves, vertical integration, vertical foreclosure

Vertical integration, technological choice and foreclosure

This article examines why, and how, fiscal decentralization could increase the economic growth rate (the hypothesis is predatory, or "corrupt", govemments). Searching for the optimal level of decentralization, the article first investigates the effects of an horizontal partition of the political power. Two effects will compete : a positive effect due to "proximity" and a negative effect linked to "coordination failures" (for raisons of externalities, small independent régions failed to implement a sufficient level of public spending). Then, the analysis seems to provide a theory of frontiers. But the article also shows that the intervention of a super-center (even corrupted), which centralizes taxes and decentralizes spending, should realize a higher growth rate. In that way, "federalism", which rather is a vertical partition of the political power, is the optimal rule.

Equilibrium strategic overbuying

We consider two firms competing both to sell their output and purchase their input from an upstream firm, to which they offer non-linear contracts. Firms may engage in strategic overbuying, purchasing more of the input when the supplier is capacity constrained than when it is not in order to exclude their competitor from the final market. Warehousing is a special case in which a downstream firm purchases more input than it uses and disposes of the rest. We show that both types of overbuying happen in equilibrium. The welfare analysis leads to ambiguous conclusions.entry deterrence, overbuying, vertical contracting

Strategic Delays of Delivery, Market Separation and Demand Discrimination

We show that an adequate choice of delays to deliver a durable good allows a monopolist to soften the intra-brand price competition between his two retailers on two different markets, when consumers suffer a switching cost to buy on the market where they are not located. To prevent each retailer from selling on both markets, the upstream producer increases the delay of delivery on the market where the willingness to pay is the lowest. It therefore separates the markets across time, by orientating consumers to the appropriate downstream retailer. Consumers pay their highest valuation, and a price differential higher than the switching cost persists in equilibrium. We discuss the application of our findings to the European car market.durable good, switching cost, discrimination, intrabrand competition, European car market

Start-ups, firm growth and the consolidation of the French biotech industry

Based on an original dataset, we analyze empirically the determinants of firm growth in the French biotech industry during two periods, 1996-1999 and 1999-2002. We have two main results. First, Gibrat's law is violated. The growth of annual turnover is influenced by teh initial size of the firm. The effect is non-linear, negative for small firms. Second, location has a significant impact on growth. We use different sets of dummies to characterize location and different measures of firm growth. As a whole, our results point at Marseilles (and its region) and Nanterre (but not Paris and Evry) as favorable places for the growth of firms between 1999 and 2002. For the 1996-1999, the favorable places are Strasbourg (and Alsace) and Rh“ne-Alpes (Lyon/Grenoble). Our analysis thus suggests that the changes in the (notably legal) environment of French biotech firms that took place in 1999 had a drastic effect of the comparative advantages of locations for biotech firms.BIOTECHNOLOGY; INDUSTRIAL CLUSTERING; FIRM GROWTH; FRANCE

Wigner islands with electrons over helium

We present here the first experimental study of Wigner islands formed by electrons floating over helium. Electrons are trapped electrostatically in a mesoscopic structure covered with a helium film, behaving as a quantum dot. By removing electrons one by one, we are able to find the addition spectrum, i.e. the energy required to add (or extract) one electron from the trap with occupation number $N$. Experimental addition spectra are compared with Monte Carlo simulations for the actual trap geometry, confirming the ordered state of electrons over helium in the island.Comment: 12 pages, 13 figures, draft pape

Upstream market power and product line differentiation in retailing

International audienceThe authors analyze a model of vertical differentiation in which retailers compete in product lines and may purchase a high quality good from a monopolist. The low quality good is produced by a competitive fringe. Depending on quality and cost differentials, the product lines chosen by retailers in equilibrium are either identical, completely different or partially overlapping. In the absence of upstream market power, the unique equilibrium is for retailers to offer identical product lines. They provide a detailed analysis of the link between upstream market power and product line differentiation.Cet article s'intéresse à la formation des prix et des marges en fonction des gammes de produits offertes par les distributeurs. Les auteurs considèrent un modèle de différenciation verticale avec un bien de qualité haute produit par un fournisseur en monopole et un bien de qualité basse fourni par une frange concurrentielle. Les gammes de produits offertes par les distributeurs sont endogènes. En fonction des structures de coûts et du différentiel de qualité, les gammes de produits choisies par les distributeurs peuvent être identiques, différentes ou partiellement différentes. En l'absence de pouvoir de marché en amont, les gammes offertes sont toujours identiques. Les auteurs fournissent une analyse détaillée du lien entre gammes de produits offertes et pouvoir de marché amont

On the theory of vortex quantum tunnelling in the dense Bose superfluid helium II

The quantum tunnelling and nucleation theory of vortices in helium II is reviewed. Arguments are given that the only reliable method to calculate tunnelling probabilities in this highly correlated, strongly interacting many-body system is the semiclassical, large scale approach for evaluation of the tunnelling exponent, which does not make any assumptions about the unknown dynamical behaviour of the fluid on microscopic scales. The geometric implications of this semiclassical theory are represented in some detail and its relevance for the interpretation of experimental data is discussed.Comment: 25 pages, 6 figures, revised version, to appear in Physica