The relative efficiency of ad valorem and unit taxes is analyzed for oligopolistic markets. We provide a simple proof that ad valorem taxes welfare-dominate unit taxes in the short run if production costs are identical across firms. The proof covers a wide range of market conduct and...

We analyze the incidence of ad valorem and unit excise taxes in an oligopolistic industry with differentiated products and price-setting (Bertrand) firms. Both taxes may be passed on to consumers by more than 100 percent, and an increase in the tax rate can increase short run firm profits (and...

We describe firm pricing when consumers search passively and follow simple reservation price rules. In stark contrast to other models in the literature, this approach yields equilibrium price dispersion in pure strategies even when firms have the same marginal costs. In equilibrium, lower price...

We revisit the fundamental issue of market provision of variety associated with Chamberlin, Spence, and Dixit-Stiglitz when firms sell multiple products. Both products and firms are (horizontally) differentiated. We propose a general nested demand framework where consumers first decide upon a...

There is a strong economic rationale for close cooperation between the public and private sectors. This has resulted in a significant increase in the demand for the provision of public services through instruments combining public and private money such as public-private partnerships (PPPs or...

Certains domaines associés aux thèmes discutés ici échappent à mes compétences, comme par exemple l’évaluation des risques et des défauts de sûreté dans les transports. Ce qui m’a convaincu de l’importance de ce sujet, ce sont quelques conclusions très générales, je dirais...

Certain areas related to the topics under discussion here lie outside my field; for instance the evaluation of risk assessment and security deficiencies in the transport sector. What has convinced me of the importance of this subject are a few very general conclusions, indeed I would say,...

Le but de cette Table Ronde est d'évaluer les effets économiques des grands projets d'infrastructures de transport. On parle de grands projets pour désigner les bonds qualitatifs, qu'il s'agisse de négocier le tracé d'anneaux autoroutiers ou ferroviaires venant recouper la dispersion des...

The purpose of this Round Table is to assess the economic effects of major transport infrastructure projects. The term "major projects" is used to designate qualitative leaps, be it the mapping out of new road or rail rings to link disparate radial penetration routes or the introduction of...