  In research and policy-making guidelines, the single-bidder rate is a
commonly used proxy of corruption in public procurement used but ipso facto
this is not evidence of a corrupt auction, but an uncompetitive auction. And
while an uncompetitive auction could arise due to a corrupt procurer attempting
to conceal the transaction, but it could also be a result of geographic
isolation, monopolist presence, or other structural factors. In this paper we
use positive-unlabelled classification to attempt to separate public
procurement auctions in the Russian Federation into auctions that are probably
fair, and those that are suspicious.
