  In this study, the scientific performance of Italian and Norwegian university
professors is analysed using bibliometric indicators. The study is based on
over 36,000 individuals and their publication output during the period
2011-2015. Applying a multidimensional indicator in which several aspects of
the research performance are captured, we find large differences in the
performance of men and women. These gender differences are evident across all
analysed levels, such as country, field, and academic position. However, most
of the gender differences can be explained by the tails of the distributions-in
particular, there is a much higher proportion of men among the top 10%
performing scientists. For the remaining 90% of the population, the gender
differences are practically non-existent. The results of the two countries,
which differ in terms of the societal role of women, are contrasting. Further,
we discuss possible biases that are intrinsic in quantitative performance
indicators, which might disfavour female researchers.
