The growth of the states' economic potential in most countries of the world in recent decades has sharply increased interest in effectiveness and efficiency of public administration. The purpose of this article is to analyze a group of approaches elaborated to replace the New Public Management. They are focused on the concept of co-production, which is strengthening the participation of citizens during decision-making and implementation. We rely on economic concepts, including that of opportunistic behavior, and principalagent model, to introduce and analyze the concept of co-production action of an individual. Within the theoretical framework of Public Administration, there is a lack of attention to the economic concepts among research of Co-production of Public Services, Public Value and New Public Governance. Besides, the fact that public services belong to different types of economic goods, such as search, experience and credence ones, is also neglected; no consistent delimitation of services and customer support is provided; practical recommendations for improving public administration in natural states ignore the results of studies on the social preferences of individuals. We conclude that the analyzed concepts do not go beyond the Public Administration Theory assumptions, which have led to the emergence and mass dissemination of New Public Management approach. Without the change this article proposes, improving effectiveness and efficiency of public administration is hardly capable.