This paper briefly describes the emergence of the relevant market concept in antitrust analysis, sets out its meaning and considers some controversial issues surrounding the concept, particularly with respect to substitution at the demand and at the supply side. Moreover, I sketch the way in...

Upward pricing pressure has recently become an important analytical tool in horizontal-merger assessment, where it is taken as a measure for the incentives of the merged firm to raise prices. I propose a comprehensive measure for pricing pressure, applicable to any off-equilibrium situation,...

A method is proposed to aggregate product-by-product elasticities over groups of products so as to obtain aggregate group-by-group elasticities. It is shown that price-cost margins charged by multi-product firms can be written as minus an aggregate inverse elasticity, just as the traditional...

The paper briefly describes the emergence since the 1950s of the concept of antitrust market, the hypothetical-monopolist approach for the definition of what was called the relevant market, the way in which it found broad acceptance among antitrust agencies around the world, some of its...

In this article a description is given of what exactly market participants are free to do in a free market, under what conditions market freedom leads to economic efficiency, why a free-market system cannot be expected to lead to socially acceptable outcomes and how competition policy is...

There are two standard versions for one-shot oligopoly games: the Cournot game and the Bertrand game. The common feature is that in both games the strategic variables are supply curves. Under Cournot the supply curves are vertical lines in price-quantity space, under Bertrand they are horizontal...

Whether a two-sided platform faces a critical-mass problem in its start-up phase depends on how difficult it is to get each of the sides on board when the other side is not yet there – the so-called chicken-and-egg problem. If there is no chicken-and-egg problem, there is no critical-mass...

Collusion, particularly collusion is in the form of hardcore cartel behavior, is the worst antitrust offense of all. People engaging in such conduct should be punished severely. That is the consensus among antitrust officials. I argue against, that collusion is not that bad as antitrust...

In this essay I argue that economics has not played the role it should have played in the resolution of competition cases and that it is unlikely that it ever will. Thus far competition analysis has put up a smokescreen of sophistication around a number of vaguely defined concepts, such as...

This brief note is a reply to the paper Two-sided Red Herrrings by Evans and Schmalensee (E&S), in which they denounce attempts by commentators in the American Express case to marginalize the findings of the literature on multi-sided platforms. In my view E&S are right in most of their...