Recent paper just published in the journal "Scientometrics" in the link above. On this issue, it's worth seeing the German method. In the paper below check in page 8 the section "The German system of appointing professors" http://www.geaba.de/wp-content/uploads/2017/07/DP_17-22.pdf And also a paper by the German Professor Reinhard Kreckel that compares the Academic career in 5 countries, Germany, France, UK, USA and Russia: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2924590
It would also be most important to examine these different tenure systems taking into consideration the inbreeding rate of the different countries. Let´s not forget that German and American universities have low inbreeding rates while Portugal, Spain, Italy and France have much higher levels: Portugal (91%), Spain (88%), Italy (78%), France (65%), UK (5%) and Germany (1%).https://www.nature.com/articles/35075637
Of course, i disagree with Navarro & Rivero in what concerns the major disadvantage of high inbreeding rates. In my view is not scientific productivity nor it is "cognitive rigidity" and corruption the "cognitive rigidity" recently mentioned in here https://arxiv.org/pdf/1802.01002.pdf but instead, a corruption-related effect as was formulated by Full Professor José Ginés-Mora:
"Inbreeding is a consequence of corruption: the family member, friend or simply the "customer" is favored from whom fidelity is expected in the future"https://www.universidadsi.es/los-efectos-perversos-de-la-endogamia-universitaria/
