“…The proposed aim of this paper has been to advance understanding of institutional theory by evaluating if its framework is appropriate for explaining variations across the EU-level in informal payments. While the institutional asymmetry explanation has been previously evaluated in other contexts (e.g., construction services; Horodnic et al, 2022b ) and regions (e.g., Central and Eastern Europe or South-eastern Europe; Williams and Horodnic, 2018a , b ) and the role of trust in shaping consumer and patient behavior has been extensively evaluated in literature ( Kukutschka, 2021 ; Pop et al, 2022 ), the institutional trust explanation (trust in institutions) is rarely evaluated as a determinant of informal payments by patients. As such, the influence of institutional trust and institutional asymmetry as determinants of such payments is tested for the first time across all 27 EU countries.…”