Working papers SES

Working papers SES
The Working Papers SES collection is a series of research papers authored by members of the Faculty of Economics and Social Sciences of the University of Fribourg (Switzerland). This series exists since 1980 and the themes investigated reflect the different scientific orientations of the Faculty: economics, business administration, computer management, quantitative methods, social sciences and media and communication sciences. The contents of the research papers are the sole responsibility of their authors.
Université de Fribourg

Simple Statistical Screens to Detect Bid Rigging

Imhof, David

(Working Papers SES ; 484)

The paper applies simple statistical screens to a bid-rigging cartel in Switzerland, and shows how well the screens detect it by capturing the impact of collusion on the discrete distribution of the bids. In case of bid rigging, the support for the distribution of the bids decreases involving a lower variance, illustrated by the coefficient of variance and the kurtosis statistic. Furthermore,...

Université de Fribourg

Econometric tests to detect bid-rigging cartels: does it work?

Imhof, David

(Working Papers SES ; 483)

This paper tests how well the method proposed by Bajari and Ye (2003) performs to detect bidrigging cartels. In the case investigated in this paper, the bid-rigging cartel rigged all contracts during the collusive period, and all firms participated to the bid-rigging cartel. The two econometric tests constructed by Bajari and Ye (2003) produce a high number of false negative results: the tests do...

Université de Fribourg

Screening for bid-rigging - does it work?

Imhof, David ; Karagök, Yavuz ; Rutz, Samuel

(Working Papers SES ; 468)

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,...