All the economic factors are changeable. With the pace of time, the factors like population, capital, technology, production method, forms of business organization, nature and desire of people etc change that affect to the aggregate demand and aggregate supply. In this macro dynamics, we discuss the process of change from one equilibrium level to another equilibrium level. It is adopted to see the transition from one position of equilibrium to another through time or process of disequilibria.
Economists D.H. Robertson, M. Kalecki, P.A. Samuelson, J.R. Hicks, and Ranger Frisch etc developed macro dynamics. According to Prof. Hicks, “Economics dynamics is those parts where every quantity must be dated.” It way, Ranger Frisch said, “It is a system in which variables at different points of time are involved in an essential way.” According to Kurihara, “Macro dynamics treats discrete movement or rates of change of macro variables.” In a dynamic economy, data change and economic system takes time to adjust it accordingly. We may now conclude with the word of Prof. Kuznets, “Economic theory which seeks to explain the phenomena of economic change, the implications of such change, and to examine the factors at work in bringing about a given change and trace the process of that change and the consequences of succeeding movements step by step is called economic dynamics.”