Economic and mathematical modelling of investments in Ukraine

Investments, primarily in manufacturing, are a guarantee that enterprises will be able to update their production assets in a timely manner and maintain or even strengthen their position in markets of goods and services. However, the issue of defining factors that affect the volume and dynamics of investments is quite problematic, which makes it difficult to create appropriate economic and mathematical models. Foreign and Ukrainian scientists have long been engaged in determining such factors. Usually, they include: GDP per capita of the country; the rate of economic growth; national savings; currency exchange rate; inflation; discount rate; the level of tax burden (primarily – corporate income tax); the price index for industrial products; the level of income on invested capital (return on investment coefficient); wages; labor productivity, etc. But in each country, the strength of influence of different factors may vary. The process of modeling investments is also complicated by the fact that some factors (for example, GDP per capita) are complex in themselves and depend on other factors. Therefore, the objective of this paper is to define the factors influencing investment in Ukraine and to develop appropriate economic and mathematical models, which are supposed to be used in the future to build a comprehensive system-dynamic model of the impact of digitalization on ensuring sustainable development of Ukraine. Such a comprehensive model can become not only a convenient tool for determining the consequences for industry of changes in investment volumes under the influence of various factors, but also the level of Labor morbidity and environmental pollution. According to results of the study, it was found that the volume of investment in the Ukrainian industry is most affected by the NBU discount rate. The paper suggests an appropriate investment model and justifies its adequacy. Investments in industrial digital capital are influenced by the factors of the US dollar index and tax burden, and investments in environmental digital capital are affected by factor of tax burden. However, due to the very approximate statistics on which the calculations were performed, the corresponding models are not reliable. Taking into account the results of the study, recommendations for the development of a methodology for collecting and presenting statistical information related to investments in digital equipment and technologies by enterprises of the country and digital capital for environmental and industrial purposes (by structure) are made. Their implementation will make it possible to make more accurate calculations in the future and create more reliable economic and mathematical models that can become a convenient tool for defining the directions of development of the country's economy.