The 2002 Royal Commission’s report concerning irregularities in the Dutch construction industry proved that the construction industry participated in illegal practices, ranging from fraud, unjustified subsidies, and license issuance to real bribery and money or favors to individual politicians or high-ranking public servants; from undercutting the market, monopolization, and forcing up prices, to selective control by partial inspectorates. The objective of the Royal Commission’s inquiry was to gain an insight into the nature and extent of the irregularities and the role of the authorities as both client and law enforcement. In conducting the inquiry, collusion was identified as the key problem. The Commission distinguished three forms of collusion: collusion between contractors themselves, such as illegal price fixing; collusion between the authorities and the construction sector, such as favoritism; and collusion at the individual level as the pathway to bribery of public officials in the positions of authority. In the Commission inquiry, a distinction was made between corruption and collusion. Corruption research often mentions collusion as a cause, condition, or explanation of corruption. References