Optimal Governance of Government Purchase of Public Services Based on Service Providers’Speculative Game

（Business school，Beijing Wuzi University，Beijing 101149，China）

Abstract：In public service procurement projects，some service chambers of Commerce take advantage of information asymmetry and contract incompleteness to seek speculation through various technical means ，so as to maximize their own interests，increase costs to units，add financial burden and have a negative impact on the society. Aiming at the speculation of service providers in the supply of public services，from the perspective of government regulation，the author constructs an evolutionary game model between service providers and government regulators ，and uses Game theory and Vensim simulation tool to analyze the impact of evolutionary stability strategies and parameter changes on evolutionary stability results in four cases. The results show that：the amount of subsidies obtained by service providers and the cost of speculation ，and the regulatory investment and regulatory income of government regulators are the main factors affecting the strategic choice between service providers and government regulators；and there are some restrictions on the punishment effect，and there is also the possibility of failure. Therefore，two suggestions are put forward. First，we should fully rely on the positive incentive effect of subsidies or rewards，increase the cost of illegal efforts and reduce the cost of supervision investment to build a supervision guarantee mechanism. And second，the government should incorporate the operation supervision of public service projects into the work assessment；when formulating the supervision strategy，it should be clear that，under the condition of government supervision， the role of punishment will play a deterrent effect ；the supervision of government regulators should also be put on the agenda ；and if the government regulators have dereliction of duty，they should be severely punished.

Key words：public services；government supervision；Game；speculation；punishment