**5. Conclusions and Further Research**

Over the last two decades, several important changes occurred in the European banking industry, leading to increased competition and pressure on bank profitability.

On the whole, the findings of this work highlight that if bank managers want to protect their performance, they will have to improve cost managemen<sup>t</sup> efficiency.

In a very difficult economic and financial environment, the challenges of banks in a bank-oriented system are enormous and include low-interest rates, intense pricing competition for commercial and mortgage loans and higher operating costs, particularly related to regulatory compliance, technology, and health care. For this reason, the use of economies of scale is important, and the managemen<sup>t</sup> decisions and specific factors of each bank, are determining factors for bank performance and efficiency.

This work points out the factors that lead to a bank being classified as efficient change, which confirms the importance of the economic environment in a way that could affect the bank performances, aside from the bank level features.

The new European regulation has been important, but the fact that in a universe of 564 DMUs (94 banks used in the value-based DEA method observed in six consecutive years) only 20 have been considered efficient shows that there is still a long way to go.

The main limitation of this study is related to the number of banks listed by country. So, for future research it would be interesting to analyze other markets and integrate institutional and ownership factors, with very different characteristics in civil law and common law countries; to compare the determinants of efficiency in the bull and bear periods also considering different external factors such cultural and market sentiment factors.

The results obtained could help managers, investors or governments to know how to improve the efficiency of their banking sector, which is the engine of the economy for civil law countries.

**Author Contributions:** Conceptualization, M.E.D.N. and M.D.C.G.; methodology, M.E.D.N. and M.D.C.G.; software, M.D.C.G. and M.E.D.N.; validation, M.E.D.N., M.D.C.G. and C.A.N.P.; formal analysis, C.A.N.P.; investigation, M.E.D.N., M.D.C.G. and C.A.N.P.; resources, M.E.D.N.; data curation, C.A.N.P.; writing—original draft preparation, M.E.D.N., M.D.C.G. and C.A.N.P.; writing—review and editing, M.E.D.N., M.D.C.G. and C.A.N.P.; visualization, M.D.C.G.; supervision, M.E.D.N.; project administration, M.E.D.N. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 006971 (UID/SOC/04011); Funding Reference: POCI-01- 0145-FEDER-006971]; and national funds, through the FCT—Portuguese Foundation for Science and Technology under the projects, UIDB/04011/2020 and UIDB/00308/2020.

**Conflicts of Interest:** The authors declare no conflict of interest.
