MATHEMATICAL TOOLS AS A COMPONENT OF THE TAX CONSULTING SYSTEM:
A METHODOLOGICAL PERSPECTIVE

Serhii RYLIEIEV

Chernivtsi Institute of Trade and Economic of SUTE, Chernivtsi

https://orcid.org/0000-0002-2058-1004

Iryna DRIN

Chernivtsi Institute of Trade and Economic of SUTE, Chernivtsi

https://orcid.org/0000-0002-0258-7007

Mykola SKRYPNYK

Chernivtsi Institute of Trade and Economic of SUTE, Chernivtsi

https://orcid.org/0000-0003-3597-6188

DOI: http://doi.org/10.34025/2310-8185-2026-1.101.11

Keywords: mathematical tools, tax consulting, correlation-regression analysis, optimization model, linear programming, effective tax burden, alternative taxation systems, cluster analysis, mathematical modeling, Tax Code of Ukraine.

---

Summary

The purpose of the article is to systematize and substantiate the methods of mathematical tools used in the tax consulting system, to develop an optimization model for choosing the optimal taxation system for an enterprise, and to empirically test a correlation-regression model for quantitative assessment of the effective tax burden. The following methods were applied: correlation-regression analysis, linear programming, cluster analysis, simulation modeling. A classification of mathematical tools by five functional groups is proposed. A linear programming problem was developed and numerically tested under 2026 conditions (minimum wage 8,647 UAH; military levy mandatory for simplified tax payers from January 2025): selecting the 2nd group of unified tax yields total tax liabilities of 305.1 thousand UAH and an effective tax burden of 4.36%, compared to 769.9 thousand UAH (ETR 11.00%) under the general taxation system. The increase in absolute tax liabilities relative to earlier estimates reflects the growth of the minimum social contribution base and the introduction of the military levy. A regression model ETR = β₀ + β₁·ROA + β₂·LEV + β₃·SIZE + β₄·INTAN + ε was tested on 60 small and medium enterprises (R² = 0.612). The results confirm that profitability, leverage and intangible asset intensity are statistically significant determinants of effective taxation. Findings can be used by consulting companies for analytical decision-support and by taxpayers for optimizing their tax liabilities under the Tax Code of Ukraine.

---

Biographies of authors:

Serhii RYLIEIEV,

Chernivtsi Institute of Trade and Economics of SUTE

Candidate of Economic Sciences, Associate Professor,

Associate Professor Department of Finance, Accounting and Taxation

Iryna DRIN,

Chernivtsi Institute of Trade and Economics of SUTE

Candidate of Physical and Mathematical Sciences, Associate Professor,

Associate Professor Department of Finance, Accounting and Taxation

Mykola SKRYPNYK,

Chernivtsi Institute of Trade and Economics of SUTE

Candidate of Economic Sciences, Associate Professor,

Associate Professor Department of Finance, Accounting and Taxation

---

References:

Bonucchi, M., Ferrari, M., Tomasini, S., & Tsenova, T. (2015). Tax Policy, Investment Decisions and Economic Growth. Revue de l'OFCE, 141(5), 225–262. https://doi.org/10.3917/e.reof.141.0225

Dragan, O., Brekhova, S., & Nagorichnoi, O. (Eds.). (2020). Improving the Tax System of Ukraine in the Context of Challenges and Threats Caused by the Spread of COVID–19. University of the State Fiscal Service of Ukraine. https://lnk.ua/TFBzjW8VG (in Ukr.).

Fejzaj, E., & Gjon, A. (2021). Impact of Tax Structure on the Business Environment. Balkan and Near Eastern Journal of Social Sciences, 7(01), 29–33. https://www.ibaness.org/bnejss/2021_07_01/04_Fejzaj_and_Gjoni.pdf

Ivanov, Yu. (2003). Alternative Taxation Systems. Tornado. https://ndc-ipr.org/media/ndc_old/documents/ASO_2003.pdf (in Ukr.).

Ivanov, Yu., Mayburov, I., Agarkov, G., Vyshnevsky, V., Vietska, O., Davyskiba, K., Danilov, O., Desyatnyuk, O., Dorozhkina, G., Ermakova, O., Karpova, V., Krysovaty, A., Lukyanenko, O., Melnyk, V., Merkulova, T., Naidenko, O., Pogorletsky, O., Sokolovska, A., Tyshchenko, O., . . . Yutkina, T. (2010). Tax Policy: Theory, Methodology, Tools. INZhEK. https://ndc-ipr.org/media/ndc_old/documents/3_sa5omLX.pdf (in Ukr.).

Karpova, T. (2020). Mechanism of Efficient Functioning of Enterprises: Tax Aspect. Economiсs and Organization of Management, 3(39). 121–132. https://doi.org/10.31558/2307-2318.2020.3.11 (in Ukr.).

Klochkovska, V., & Klochkovskyi, O. (2021). Modern Features of Taxation in Ukraine. Economiсs and Organization of Management, 2(42), 86-93. https://doi.org/10.31558/2307-2318.2021.2.9 (in Ukr.).

Krysovaty, A., Melnyk, V., & Koshchuk, T. (2014). Tax Transformations in the EU and Tax Policy of Ukraine in the Context of European Integration (A. Krysovaty, Ed.). Ternopil National University of Economics. https://lnk.ua/oiZuhwIqs (in Ukr.).

Maliarchuk, O., Rylieiev, S., & Drin, I. (2024). Financial and Tax Aspects of Company Activity Planning: Econometric Analysis. Bulletin of the Chernivtsi Trade and Economic Institute, 2(94), 79–95. http://doi.org/10.34025/2310-8185-2024-2.94.06 (in Ukr.).

On Amendments to the Tax Code of Ukraine to Improve Tax Administration, Eliminate Technical and Logical Inconsistencies in Tax Legislation, Law of Ukraine № 466-IX (2022) (Ukraine). https://zakon.rada.gov.ua/laws/show/466-20#Text (in Ukr.).

On the State Budget of Ukraine for 2026, Law of Ukraine № 4695-IX (2025) (Ukraine). https://zakon.rada.gov.ua/laws/show/4695-20#Text (in Ukr.).

Onisiforova, V., & Sidelnikova, V. (2019). Simplified System Of Taxation: Modern State, Advantages, Disadvantages And Prospects. Problems and Prospects for the Development of Entrepreneurship, 2(23), 158–166. http://doi.org/10.30977/PPB.2226-8820.2019.23.0.158 (in Ukr.).

Revenko, O. (2021). The Influence of Tax Factors on the Enterprise Results. Effective Economy, 8. https://doi.org/10.32702/2307-2105-2021.8.78 (in Ukr.).

Tax Code of Ukraine, Code of Ukraine № 2755-VI (2026) (Ukraine). https://zakon.rada.gov.ua/laws/show/2755-17#Text (in Ukr.).