The paper is devoted to the investigation of environmental, energy and economic security by multivariate analysis methods. A set of indicators selected for research conducting includes 9 parameters for each security type. Study sample is formed by data for 6 Eastern European countries (Ukraine, Moldova, Poland, Romania, Hungary and Slovak Republic) for the period 2000–2019. Empirical study was conducted by factor analysis, which allowed identifying the main components of environmental, energy and economic security. Comparison of the results obtained for the studied countries showed differentiation of individual profiles of such types of security. Investigation of integral vectors of environmental, energy and economic security showed the highest level of interaction between energy and environmental security and the lowest one between energy and economic security.

Purpose. To identify the current level and trends of convergence to justify the directions of adjustment of approaches to the management of the national economy. Methodology. The methodological basis of the study is economic and mathematical modelling using Barro-regression and variational analysis. Integral indicators for the characteristics of the components of the studied chain are defined as the arithmetic mean of partial indicators of economic development (24 indicators), educational development (28 indicators), digitalization (12indicators) and national security (53 indicators), normalized by the method of natural normalization. To assess the pairwise, triple and complex convergent relationships in the studied chain, a multiplicative convolution of the corresponding integral indicators characterizing a pair, triple or four of the studied concepts, was performed. The sample consisted of 11 countries from Central and Eastern Europe (Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia, Slovenia, Ukraine). The research period includes 19992020. Findings. The existence of dynamic convergent links in the national security digitalization, education national security digitalization chains is confirmed, which indicates the need for further interstate integration of regulatory practices in the field of digitalization impact on the national security (including digital education effects). The links in the economy education, economy national security, education national security, economy education national security chains have a fairly high static level of convergence, which indicates the need to level the differences in national practices of regulation of these directions. At the same time, current trends in the digitalization of education and the digitalization of the economy remain quite diversified, which determines the need to apply specific national government practices in this area. Originality. Methodological principles of integrated assessment of convergent relationships in the economy education national security digitalization chain differ from the existing ones by using integrated indicators of characteristics of single, pair, triple and complex relationships within the studied chain to determine the levels of their - and -convergence. This allowed identifying the presence of the achieved level of convergence and dynamic convergent trends that arise in the process of economic and educational transformations in the context of overcoming security challenges in the national economy in the context of digitalization. Practical value. The achieved significant level of convergence of the economy, education and digitalization of the studied countries has been revealed, as well as stable convergent links of integrated development of their economy, education and national security have been formed. The results obtained can be used as a scientific substantiation of adjustment of directions of state regulation of economy and education in the conditions of digitalization and in the context of overcoming security challenges.

The growing level of modern environmental problems and the need to ensure energy security creates new challenges for the development of the energy sector. Nowadays, countries must balance their international competitiveness and progress in achievement the Sustainable Development Goals. This provides a necessity for the development of alternative energy technologies. Modern trends in the development of alternative energy indicate a gradual increase in the relevance of biofuel production. At the same time, the development of clean energy technologies needs significant investments, and their commercial implementation is a long process. Moreover, energy industry transformations require significant changes in the functioning of complementary spheres. That makes necessary the use of additional incentives for the development of the bioenergy sector. Thus, an assessment of the impact of environmental taxes on biofuel production and consumption becomes crucial. This research is aimed at the identification of contextual and causal relationships between environmental taxation (transport and energy taxes) and biofuel production and consumption. Contextual links were identified by the methods of bibliometric analysis (VOSviewer and Google Books Ngram Viewer results), while causal links were determined by the methods of panel regression modeling (panel-corrected standard errors model) with a time lag from 0 to 4 years. A sample of nine European countries (Austria, France, Germany, Hungary, Italy, The Netherlands, Poland, Spain, U.K.) was formed for the assessment. The research period includes 2010–2020. The conducted bibliometric analysis proved the presence of a wide range of relationships between environmental taxation and the development of the bioenergy industry. Panel regression modeling proved the existence of a significant impact of environmental taxation on the volumes of biofuel production and consumption. The increase in revenues from transport and energy taxes determines the growth in indicators of biofuel production and consumption. Such effects are medium term for transport taxes and short term for energy taxes. These results made a huge contribution in the development of the system of state regulation methods of alternative energy stimulation and energy production and consumption transformations.

The growing importance of climate change and the depletion of natural resources, as well as geopolitical risks associated with the distribution of energy resources, cause an increase in the urgency of ensuring energy security. In modern conditions, the criteria of energy security are the level of production of traditional and renewable energy, the efficiency of energy production, the rationality of its consumption, and the level of pollution arising in the process of the functioning of the energy sector. Different types of regulatory instruments are used internationally to achieve different goals related to energy security. This study involves testing the hypothesis that the effectiveness of energy taxes in ensuring energy security is determined based on the choice of the object of taxation and should be measured via the complex effect of changes in various parameters of energy security. To test this hypothesis, a sample of data from 24 European countries for the period 1994–2020 was formed and energy taxes were grouped into 12 groups (energy taxes on the consumption of different energy sources, energy taxes on fossil fuels, taxes on electricity consumption, taxes to stimulate renewable energy production, contributions to energy funds, etc.). The assessment was carried out with the help of panel regression modeling tools with the installation of a three-year time lag in the model. This method made it possible to determine the short- and medium-term effects of the regulatory influence of certain types of energy taxes. Moreover, the research provides an assessment of the regulatory effectiveness of various types of energy taxes across countries with different initial structures of energy production. The obtained results proved that the comprehensive efficiency of different types of energy taxes is different and depends on the features of the construction of the country’s energy system. In general, complex energy taxes are the most effective method of taxation, while contributions to energy funds are the least effective method of taxation. In the countries with energy systems based on fossil fuels, taxes on mineral oils are the most effective in ensuring of energy security, as well as in the countries with a high initial level of renewable energy use, while complex energy taxes are the most effective in the countries with well-diversified energy systems. This study creates the basis for improving strategies for the use of regulatory instruments of energy transformation in building a clean, secure, and sustainable energy system for the country.