<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>Huber, Martin</dc:creator>
  <dc:creator>Imhof, David</dc:creator>
  <dc:creator>Ishii, Rieko</dc:creator>
  <dc:date>2020-10-01</dc:date>
  <dc:description xmlns:ns0="xml" ns0:lang="en">We investigate the transnational transferability of statistical screening methods  originally developed using Swiss data for detecting bid-rigging cartels in Japan. We  find that combining screens for the distribution of bids in tenders with machine  learning to classify collusive vs. competitive tenders entails a correct classification rate  of 88% to 93% when training and testing the method based on Japanese data from  the so-called Okinawa bid-rigging cartel. As in Switzerland, bid rigging in Okinawa  reduced the variance and increased the asymmetry in the distribution of bids. When  pooling the data from both countries for training and testing the classification models,  we still obtain correct classification rates of 82% to 88%. However, when training the  models in data from one country to test their performance in the data from the other  country, rates go down substantially, due to some screens for competitive Japanese  tenders being similar to those for collusive Swiss tenders. Our results thus suggest  that a country’s institutional context matters for the distribution of bids, such that a  country-specific training of classification models is to be preferred over applying  trained models across borders, even though some screens turn out to be more stable  across countries than others.</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>https://folia.unifr.ch/global/documents/308994</dc:identifier>
  <dc:identifier>https://folia.unifr.ch/documents/308994/files/WP_SES_519.pdf</dc:identifier>
  <dc:language>eng</dc:language>
  <dc:relation>http://www.unifr.ch/ses/wp</dc:relation>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>License undefined</dc:rights>
  <dc:subject xmlns:ns1="xml" ns1:lang="en">Bid rigging</dc:subject>
  <dc:subject xmlns:ns2="xml" ns2:lang="en">screening methods</dc:subject>
  <dc:subject xmlns:ns3="xml" ns3:lang="en">machine learning</dc:subject>
  <dc:subject xmlns:ns4="xml" ns4:lang="en">random forest</dc:subject>
  <dc:subject xmlns:ns5="xml" ns5:lang="en">ensemble methods</dc:subject>
  <dc:subject>info:eu-repo/classification/udc/33</dc:subject>
  <dc:title xmlns:ns6="xml" ns6:lang="en">Transnational machine learning with screens for flagging bid-rigging cartels</dc:title>
  <dc:type>http://purl.org/coar/resource_type/c_18ws</dc:type>
</oai_dc:dc>
