  The Internet Domain Name System (DNS) is a hierarchical name space that
enables the assignment of unique, mnemonic identifiers to Internet hosts and
the consistent mapping of these names to IP addresses. The root of the domain
name system is the top of the hierarchy and is currently managed by a
quasi-private centralized regulatory authority, the Internet Corporation for
Assigned Names and Numbers (ICANN). This paper identifies and discusses the
economic and policy issues raised by competing DNS roots. The paper provides a
precise definition of root-competition and shows that multiple roots are a
species of standards competition, in which network externalities play a major
role. The paper performs a structural analysis of the different forms that
competing DNS roots can take and their effects on end-user compatibility. It
then explores the policy implications of the various forms of competition.
  The thesis of the paper is that root competition is caused by a severe
disjunction between the demand for and supply of top-level domain names. ICANN
has authorized a tiny number of new top-level domains (7) and subjected their
operators to excruciatingly slow and expensive contractual negotiations. The
growth of alternate DNS roots is an attempt to bypass that bottleneck. The
paper arrives at the policy conclusion that competition among DNS roots should
be permitted and is a healthy outlet for inefficiency or abuses of power by the
dominant root administrator.
