Gas Transport in Porous Media: Simulations and Experiments on Partially Densified Aerogels

The experimental density dependence of gas (argon and nitrogen) permeability of partially densified silica aerogels in the Knudsen regime is quantitatively accounted for by a computer model. The model simulates both the structure of the sintered material and the random ballistic motion of a point particle inside its voids. The same model is also able to account for the densit y dependence of the specific pore surface as measured from nitrogen adsorption experiments.Comment: RevTex, 11 pages + 5 postscript figures appended using "uufiles". Published in Europhys. Lett. 29, p. 567 (1995

Two-Sided B2B Platforms

This chapter provides a roadmap to the burgeoning literature on two-sided markets with a specific focus on BtoB market places. On-line intermediation involves two-sided network effects between buyers and sellers, and the implications for optimal BtoB platforms’ tariffs are discussed. The chapter discusses first the monopoly case, drawing attention to the distinction between upfront registration and transaction fees. Then the competitive case is discussed, with different degrees of differentiation, the distinction between single-homing and multi-homing, and different business models. The last section is devoted to non-price issues such as tying, the design of the matching process and the ownership structure.

Two-Sided Markets and Electronic Intermediaries

The object of this paper is to discuss on-line intermediation from the perspective of two-sided markets. It builds a simple model of the intermediation activity when trading partners are involved in a commercial relationship and uses it to illustrate some of the results that emerge in the two-sided market literature, as well as to discuss some new aspects. The first part concentrates on a monopoly intermediation service and discusses both efficient pricing and monopoly pricing. The second part discusses the nature of competition between intermediaries, addressing issues as competitive crosssubsidies, multi-homing or tying.intermediation, two-sided market, network, cross-subsidy, tying

The market for lawyers: The value of information on the quality of legal services

We study the value of information on the quality of legal services by analyzing the incentives of litigants to hire high-quality lawyers, the incentives of lawyers to invest in quality-enhancing activities and the effect of legal representation on the decision-making behaviour of adjudicators. In a setting where adjudicators have reputational concerns, we show that better information over the quality of legal representation generates a tradeoff. On the one hand, it allows for a better match between the value of a legal dispute and the quality of the legal representation. This also has the effect of increasing the incentives of lawyers to invest in quality-enhancing training. On the other hand, better information over the quality of legal representation may induce adjudicators to bias their decisions in favour of the litigant with the highest-quality lawyer and this generates allocative inefficiency. We discuss the implications of these effects on the desirability of quality certification system (such as the Queen’s Counselor system) in the market for the legal professions