Заболотній, Сергій ВасильовичZabolotnii, SerhiiМогілей, Сергій ОлександровичMogilei, Sergii2025-11-112025-11-112023Zabolotnii S., Mogilei S. Modifications of Evans Price Equilibrium Model. Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska. 2023. № 13(1). рр. 58-63. DOI: https://doi.org/10.35784/iapgos.3507 [Scopus]https://ph.pollub.pl/index.php/iapgos/article/view/3507/3079https://dr.csbc.edu.ua/handle/123456789/596The paper regards the classical Evans price equilibrium model in the free product market in the aspect of regarding the opportunitiesfor expanding (modifying) the model given that is aimed at perfecting the accuracy of its mathematical formulating. As an accuracy criterion, we have chosen a summary quadratic deviation of the calculated indices from the given ones. One of the approaches of modifying the basic Evans modelis suggesting there is a linear dependence between price function and time as well as its first and second derivatives. In this case, the model willbe described through differential equation of second order with constant coefficients,revealing some oscillatory process. Besides, it is worth regardinga non-linear (polynomial) dependence between demand, supply and price.The paper proposes mathematical formulating for the modified Evans models that have been approbated for real indices of exchange rates fluctuations. It also proves that increase of the differential and/or polynomial orderof the given model allows its essential accuracy perfection. Besides, the influence of arbitrary restricting circumstances ofthe model onits accuracyis regarded. Each expanded Evans model is accompanied by mathematically formulated price and time dependence.enSOCIAL SCIENCES::Business and economics::EconomicsSOCIAL SCIENCES::Business and economicsSOCIAL SCIENCES::Business and economics::Business studiesMATHEMATICSMATHEMATICS::Other mathematicsSOCIAL SCIENCES::Statistics, computer and systems science::Informatics, computer and systems scienceArticle