Abstract. This paper deepens the study of non-performing loans (NPLs), conceived by the author as an expression of non-quality of part of bank lending / loans, which is considered in turn, as being reflected directly by the proportions held by these loans in the total volume of loans (granted by banks). In this respect, it starts from conceptual delimitations required to perform the research, including a redefinition of NPLs (compared to the documentary sources in this area). A large part of paper is assigned, however, to the analyzes focused on econometric modelling, based on the determining relationships regarding the volume of NPLs, the author outlining appropriate regression models, taking into consideration the volume of these loans, both as dependent variable and as determinant variable within relationships with some macro indicators (the total volume of bank loans, GDP, etc.), included in these regression models, either as determinant or dependent variables. Testing them, by processing the corresponding data in Romania’s case, led to relevant results and conclusions, being also validated the models used.

Keywords: bank loan, loan categories, causal linkages, feedback, econometric models. JEL Classification: