policymakers demonstrate

198 Nikolaos Vettas
very different activity than it used to be. However, we could in principle have
had (and we did have) travel agents before the Internet and also we could have
(and we sometimes still have) online searches without online platforms to act
as intermediaries.
To argue that the new markets require a whole new set of research that would
make the existing one obsolete would not necessarily be a reasonable way to
proceed. Instead, the key is how to use existing results, to refine, extend and
enrich them in the context of digital markets. In particular, there are at least
two important literatures within IO that are relevant here and, by their nature,
necessarily closely related to the currently open issues. These refer to the study
of vertical relations (integration and vertical restraints) and to pricing practices:
in particular, price discrimination and nonlinear pricing. We sketch some of the
progress that has been made in areas that are still open and important. The challenges
faced by researchers in these areas are not trivial. The study of vertical
relations necessarily finds in its way the issue of bargaining between verticallylinked
firms. Such firms act both as collaborators, since they trade goods and
services with each other, and at the same time as competitors, since they compete
in sharing the joint surplus.
Pricing itself has naturally been a core issue in economics. However, we
may not have a full understanding of how pricing functions when there is price
discrimination and various types of nonlinear pricing under oligopoly competition,
when there are vertical relations, or what the welfare implications are of
the various restrictions, especially under important dynamic effects.
It is beyond the scope of this chapter to discuss in depth the important related
competition cases that have been recently examined or are under examination.
Instead, we use these as a motivation to focus on some related ideas and results
from the relevant literature. We also discuss areas and topics where further
research would be useful and possibly important for policy. This refers both to
more basic research (that could be useful across a number of competition policy
issues and other cases) and to research that is motivated by specific competition
cases.
The remainder of this chapter is organized as follows. The next section starts
with a general perspective on competition policy in the EU, before turning to
some recent developments there. We discuss digital markets and differentiate
according to the features of the goods supplied and other dimensions, since
the digital nature of each market does not have to be the same. Then we discuss
some recent competition cases in Europe (including e-books and online
travel agencies) that can serve as leading examples for the analysis and relate
to the Commission’s Single Digital Market initiative. We close this section
with a comparison between online and offline trade. Section 5.3 sketches some
selected results from the IO literature, looking at pricing (with a focus on price
discrimination) and at vertical relations (with a focus on restraints). Section 5.4