Evolutionary game analysis on decision-making behaviors of participants in mega projects

Mega projects have a huge impact on the economy and society. Preventing collusive behavior and introducing public participation in supervision are conducive to the governance of mega projects and are crucial to their success. The owner, the construction party, and the supervisor are regarded as a potential collusion-body. Based on evolutionary game theory, the paper constructs an evolutionary game model with a collusion-body, the government, and the public as participants. The stability of each participant's strategy selection is analyzed, the conditions for evolutionarily stable strategies (ESS) are obtained, and the evolutionary paths are simulated. Results show costs and benefits strongly affect all three participants. Each participant's strategy is influenced by the others, with critical probabilities at which strategy choices switch. There are five ESS in the system, each under different cost–benefit conditions. With active government intervention and public supervision, an ideal stabilization strategy can be achieved by adjusting participants’ costs and benefits, improving governance effectiveness against collusion in mega projects.