Evolution of the Sectoral Structure of the Economy: Conceptual Approaches and Contemporary Scientific Interpretations

Abstract

Abstract. The article provides a comprehensive theoretical generalization of the evolution of scientific approaches to the formation and interpretation of the sectoral structure of the economy. The study traces the development of economic thought from early mercantilist and physiocratic concepts, which associated national wealth with specific types of economic activity, to classical political economy and contemporary multisector models of post-industrial society. Based on an analysis of the works of W. Petty, A. Smith, D. Ricardo, A. Fisher, C. Clark, J. Fourastié, D. Bell, P. Drucker, M. Castells, and modern scholars, the paper systematizes conceptual interpretations of the primary, secondary, tertiary, quaternary, and quinary sectors of the economy. Special attention is paid to the academic debate on the methodological relevance of further differentiation of the tertiary sector and the justification for identifying the quaternary and quinary sectors. It is demonstrated that the growing role of knowledge, information technologies, innovation activities, strategic management, and creative industries significantly limits the explanatory capacity of the classical three-sector model when analyzing contemporary structural transformations. The study substantiates that the quaternary sector should be interpreted as a sphere of knowledge-intensive, informational, and intellectual activities, while the quinary sector encompasses strategic, managerial, cultural, and socially significant functions, including the experience economy. The article proposes a generalized five-sector model of the economy that reflects the evolutionary trajectory from agrarian and industrial societies to post-industrial, knowledge-based, and creative economies. This model enables a deeper interpretation of modern structural shifts, provides insights into the role of intellectual and managerial labor in economic development, and forms a theoretical foundation for further empirical research on sectoral dynamics in national economies, as well as for the design of effective economic policy instruments in the context of post-industrial transformation.