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Research report

Screening for bid-rigging - does it work?

BP2-STS

    02.04.2016

26

bid-rigging
screening method
variance screen
cover bidding screen
bid rotation test
partial collusion
English This paper proposes a method to detect bid-rigging by applying mutually reinforcing screens to a road construction procurement data set from Switzerland in which no prior information about collusion was available. The screening method is particularly suited to deal with the problem of partial collusion, i.e. collusion which does not involve all firms and/or all contracts in a specific data set, implying that many of the classical markers discussed in the corresponding literature will fail to identify bid-rigging. In addition to presenting a new screen for collusion, it is shown how benchmarks and the combination of different screens may be used to identify subsets of suspicious contracts and firms in a data set. The discussed screening method succeeds in isolating a group of “suspicious” firms exhibiting the characteristics of a local bid-rigging cartel operating with cover bids and a – more or less pronounced – bid rotation scheme. Based on these findings the Swiss Competition Commission (ComCo) decided to open an investigation.
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Faculty
Faculté des sciences économiques et sociales et du management
Language
  • English
Classification
Economics
Series statement
  • Working Papers SES ; 468
License
License undefined
Identifiers
  • RERO DOC 259164
  • RERO R008402581
Persistent URL
https://folia.unifr.ch/unifr/documents/304919
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