[eng] This paper analyzes the effects of banking productivity on the evolution of interest rates and the exit of entities from the Spanish banking sector during the years 2007-2015. Using a theoretical framework of competition with heterogeneity in operating costs, we propose a set of hypotheses which are tested using empirical models. The results show that the productivity of the banking industry had a moderate growth of 2% during the period analyzed, that improvements in the efficiency of the entities are transferred to a decrease in loans' interests and bank fees, and that a context of low interest rates does not necessarily imply a reduction in the intermediation margin because the entities can compensate the negative margins of the deposits with an increase in the differential of their loans with respect to the Euribor. The study also shows that the most productive entities could have taken advantage of the restructuring process to expand their offices' network in markets where they have a low presence through the absorption of less productive entities.