Agent-based computer model has been developed. This model realizes communications between different economic agents and is based on the Leontyev’s static intersectoral balance. Communications appear to be the basis of economic and social systems. Starting with the set of modeled microprocesses (behavior of individual agents) we have an opportunity to observe the states of the macroprocess – the behavior of economic system in a whole. While experiments with the model valuable results were received. These results are connected with economic system behavior under the conditions of enough money funds and their lack.