Economico-Mathematical Methods, methods of economic science and applied mathematics used in the quantitative analysis of the socialist economy as a whole and its individual components. They are an important means of cognition and are instrumental in dealing with economic development problems. Under developed socialism, the volume of production and capital investment has reached gigantic dimensions and the rate of introduction of scientific and technical achievements has been stepped up. The links and dependencies have become far more complicated not only within the framework of the economy itself but also internationally. Each year there emerge ever new possible solutions of concrete economic tasks, although they differ in cost and time of execution. Yet it is necessary to accelerate the decision-making process because of the dynamics of scientific and technical progress and changes in the economic situation. Mathematics studies spatial forms and quantitative relations of the real world and the quantitative dependences inherent in various forms of the motion of matter. Economic relations that evolve in the process of production, distribution, exchange (/) and consumption of material wealth are a most important form of the motion of matter. As such, economic relations are characterised by measure, i. e. by the unity of quality and quantity. Relations between quality and quantity are 116 manifested in the measure which serves as the groundwork for applying mathematical methods to economic studies. Methods of mathematical statistics, linear and non- linear programming, game theory, the theory of the service industry, the timetable theory, the theory of managed resources, and other economico-mathematical methods are being used in economic practice. Economic relations are always linked with the movement of things. The quantitative proportions of these material relations are the expression of the quantitative essence .of the relations of production. This opens up broad possibilities for using economic and mathematical modelling. An economic and mathematical model is the scientific reflection with the help of algebraic equations and non-equations, of real phenomena and processes on the scale of the national economy as a whole ( macromodels) or certain industries, regions, or enterprises (local models). Economic and mathematical modelling is based on the method of abstraction and the theory of reflection, widely used in political economy. The scientific principles of constructing economico-mathematical models ensure relatively full quantitative and qualitative correlations and similarity of the model and the real elements of the economic system reflected in it. The degree of abstraction and, therefore, the degree to which the model corresponds to the real object may be different depending on the objectives, information and other conditions. Depending on their form and purpose, the economicomathematical models now being used may be categorised according to the following three groups: correlatory (regressive), balance, and optimal economic models. Experience shows that the employment of economico-mathematical modelling allows production resources fo be used 10 to 20 per cent more effectively than if traditional methods were used. Better management of the economy, the necessity of taking fuller account of social requirements in the plans and satisfying these demands with the minimum expenditure of resources expand the possibilities of using economic and mathematical methods in various sectors of planned activity when drawing up forecasts of scientific and technical progress and socio-economic processes. Alongside this, a necessary condition for the fruitful use of the quantitative methods is their unbreakable link with the qualitative analysis of economic processes and phenomena on the basis of profound knowledge of Marxist-Leninist methodology (see LongTerm Planning; Economic Planning; Proportions of Social Production; Forecasting, Economic).