Abstract: The subject of the article is the multiplier effects that spread in the regional economy. The aim of the work is to identify the influence of the regional economy sectoral diversification on the value of the regional investment multiplier. The author states that the sanctions pressure on the Russian economy needs to increase the efficiency of investments in the formation of the resource potential of the regions. The regional economy investment multiplier was chosen as the basis for the efficiency improvement tool. Since the growth of its value increases the growth of GRP per unit of investment. This approach determines the need to manage the value of the regional investment multiplier. The paper presents a mathematical model that determines the dependence of the value of the regional multiplier on the degree of sectoral diversification of the regional economy. The statistical significance of the presented model was tested using data from the economy of the Ryazan and Ivanovo regions. The calculations presented in the work prove that the value of the regional investment multiplier depends on the sectoral structure of the regional economy, namely, on the degree of its sectoral diversification. The identification of this dependence forms the scientific novelty of the work, since a significant part of the existing studies is based on the matrix or scalar approach to determining the value of the regional investment multiplier, without examining its internal dependencies. The author's special contribution to the study of the topic is not only the identification of the dependence of the multiplier value on the degree of sectoral diversification of the regional economy, but also the definition of an approach to increasing the efficiency of investments due to a targeted impact on the value of the regional multiplier.

Abstract: The subject of this research is the risks generated by multiplicative processes that accompany private and public investment projects in the sphere of ensuring economic security of the country. The author examines the inflationary component of multiplicative processes, which can cause rise in the cost of the investment projects implemented in the sphere of economic security, up to their cancellation. Particular attention is given to multiplicative transfer of income gains from purposefully developed industries to adjacent or loosely related industries. Such a transfer boost the competition for resources between the industries and complicates the implementation of projects in the sphere of ensuring economic security. The following conclusions were made:
 
- The structure of the process of interaction between the investment multiplier and investment accelerator is self-similar, which simplifies its modeling;
 
- Multiplicative processes may generate risks in sphere of ensuring economic security of the country;
 
- In order to substantiate the need for implementing large investment projects, the consideration of generated multiplicative processes is required;
 
- Modeling and taking into account the multiplicative processes allows transforming them from a risk generator into an instrument that amplifies the steps of the government and private investors on ensuring economic security of the country.
 
The novelty of this research consists in the approach towards analyzing multiplicative process as a risk generator, which complicates the implementation of investment projects by shifting the impact upon the trajectory of their development.