Why might saving 5 euros on a 15-euro purchase appear more handy than saving the same amount on a 125-euro buy? And why does losing a performance ticket appear to be more expensive than losing the same amount of money? These seeming discrepancies are examples of mental accounting, which is the tendency to divide money into various psychological "accounts" based on its origin, destination, or context of use. Although each euro has the same objective economic value, it is not necessarily seen or spent the same way. A significant international study, published in the Journal of Consumer Research, conducted the first large-scale test of the validity of the effects of mental accounting across various countries and in a financial system that was significantly different from that of the 1980s, when the model was developed by Nobel Prize winner Richard Thaler and other pioneers of behavioral decision research. Professor Enrico Rubaltelli of the Department of Psychology at the University of Padua coordinated the study, which was carried out under the supervision of Giulia Priolo of the Copenhagen Business School, Martina Vacondio of the University of Trento, Federica Stablum of University College London, and Simone D'Ambrogio of the University of Oxford. The study made a significant addition to statistical analyzes thanks to the involvement of a wide multinational group of researchers who translated and altered the materials as well as organized data collecting in participating countries. The researchers wanted to see how well Thaler's classical theory held up in a vastly different economic situation. Mental accounting refers to people's inclination to mentally divide money into categories such as rent, leisure, savings, and unexpected income. This technique can help you budget and regulate your spending, but it can also lead to judgments that contradict the economic premise that money is totally interchangeable. Much has evolved since the initial research on mental accounting was completed. Cash and cheques have been gradually displaced by credit cards, online banking, digital payment systems, and subscription services. Furthermore, the original evidence was mostly derived from small US groups, often consisting of college students. The researchers investigated if the same psychological principles are still discernible now and whether they may be generalized to vastly different cultural and economic settings. Individual differences in age, education, income, and financial literacy did not significantly explain the observed variances between countries. However, a probable association with national economic conditions was discovered: in nations with a per capita GDP of less than $50,000, the usage of mental accounting increases as GDP rises; above $50,000 per capita GDP, the effect stabilizes and no variations are observed between countries.