The behaviour of unit root tests defined in terms of sign transform is here analysed. The sign transform allows us to gain robustness to non-normality. Contrarily to the standard unit root tests, our results show that these tests are very reliable in the presence of breaks, provided there is no...

The Italian gender wage gap is related to a gap in returns to education which causes a sizable glass ceiling effect. The gap is detected by quantile regressions implemented in different subsets. Quantile regressions allow computation of both the average gap and the divergence in the tails of the...