This paper estimates demand elasticities for the Turkish mobile telecommunication market. In contrast to most other studies, firm level data is used to estimate dynamic panel data models including instrumental variable techniques. Both short- and long-run elasticities are calculated, yielding a...

This paper explores the effects that collusion can have in newspaper markets where firms compete for advertising as well as for readership. We compare three modes of competition: i) competition in the advertising and the reader market, ii) semi-collusion over advertising (with competition in the...

This paper summarizes the peculiarities of online markets and discusses recent antitrust cases related to online markets. Following a brief description of the online markets' characteristics and potential tendencies for concentration the paper first discusses the antitrust allegations and...

Katz (1987), DeGraba (1990), and Yoshida (2000) have formulated theories that price discrimination bans in intermediary goods markets tend to have positive effects on allocative, dynamic and productive efficiency, respectively. We show that none of these results is robust vis-à-vis endogenous...

This paper analyses the extent of inter-format retail competition between supermarkets, discounters and drugstores in Germany, using data from the German market for diapers. We estimate a random coefficient logit model at the individual household level. Based on consumer substitution patterns,...

Given various recent antitrust investigations on the retail sector, we deal with uncovering demand systems substitution patterns for a particular market (diapers) to investigate the inter-format competition (supermarkets vs. discounters vs. drugstores). Using the uncovered demand system we...

We re-examine the view that a ban on price discrimination in input markets is particularly desirable in the presence of buyer power. This argument crucially depends on an inverse relationship between downstream firms' profits and the uniform input price. Assuming different input efficiencies...

This paper examines the causes and effects of mobile number portability (MNP) and provides a survey of its implementation in Europe. We first examine the competitive effects and the costs of introducing MNP. Next, we discuss how to charge for MNP. We argue that a price cap regime starting from...