摘要:The article examines the models of efficient functioning of trading enterprises in the conditions of economic development during 2016-2019. It is proved that the criterion for measuring efficiency is the evaluation of static and dynamic efficiency of trade activities, which allows changes in the used assets (resources) to be taken into account, an enterprise’s safety margin to be increased and it testifies to the merger (integration) of diminishing returns and economic fluctuations in modern economic macro and microsystems. The results of measuring the efficiency of trading enterprises’ activity show that in order to evaluate the efficiency of the functioning of trading enterprises qualitatively and completely, it is necessary to consider all possible factors. Given the existence of Clark’s law, the authors substantiate an approach to evaluating the performance based on simple one-factor multiple models, which proves that future studies of finding ways to improve the efficiency, which are mainly aimed at extensive resource changes, will be erroneous, unjustified, and most likely, they will reduce the effectiveness of the resource under study. By specifying and parameterising the function of an enterprise’s trade activity in the conditions of economic development, it is possible to evaluate not only the static efficiency of trade activity, but also the impact of the law of diminishing marginal product on the results of the enterprise’s operation. This approach allows us to determine the optimal boundaries of doing business and the most effective marginal size of resource changes to achieve high cost indicators and economic synergy. The article defines clear boundaries between the minimum marginal product ratio (increase in net income relative to the growth in the number of employees) and the maximum average product (productivity) of trading enterprises.