Micro static explains about the equilibrium point that is obtained by two co- operant factors that is demand and supply, under the static or given period of time. Thus equilibrium is obtained when demand equals supply under the condition of ‘other things remaining same’ or ‘no change’. When variables change, the initial equilibrium level will be disturbed. This brings the process of disequilibria and it continues till new equilibrium is obtained. In this background it is essential to analyze the comparison between these two equilibrium levels. The comparison between these two different equilibriums is studied under comparative micro-statistics. It compares one equilibrium with other equilibrium but does not identify the process of disequilibria that occurs. According to Prof. Schumpeter; “The comparative analysis of two equilibrium positions may be defined as comparative static analysis. Since, it studies the alternation in the equilibrium position corresponding to an alternation in a single datum.”
For example, suppose that income of consumer changes that affects to demand of consumer and regarding supply, initial equilibrium distributes and new equilibrium is obtained. Same way due to change in the technology, production function, then cost and hence supply change and this affects the initial equilibrium. Thus in both cases- either demand changes or supply changes, two equilibrium appear- initial and later. Comparative micro static studies those two equilibriums.
The diagram given explains the comparative micro static equilibrium. In the diagram, demand curve DD and supply curve SS gives the equilibrium point ‘E’ at price- P and quantity- Q. due to changes in the demand, it shifts to D1D1 and new equilibrium point ‘E1’ is obtained with the same supply curve SS. This new equilibrium gives new price- P1 and quantity- Q1. Comparative micro static studies the two equilibrium points ‘E’ & ‘E1’.