Temporary employment and wage gap with permanent jobs: evidence from quantile regression

Previous research on wage penalty for temporary workers has focused on the conditional mean model. This paper uses micro data from the 2006 wave of the Survey of Italian Households’ Income and Wealth (SHIW) to examine the wage gap between temporary and permanent workers across the whole wage distribution. I apply a quantile regression models to understand whether there are glass ceiling or sticky floor for fixed-term workers and to test the hypothesis of polarization of wage profile by contract status. I also exploit a counterfactual decomposition analysis to investigate whether the gap is attributed to differences in characteristics or to differences in coefficients effect. A possible source of misspecification may arise, the endogenous selection in temporary status. In order to address the selectivity bias, I adopt an IV specification and a variant of the traditional Heckman (1978) dummy endogenous variable for the quantile framework. The main finding is a sticky floor effect, in the sense that the wage penalty for temporary workers is wider at the bottom of earnings distribution and in particular the decomposition method shows how the coefficients effect is decreasing in the upper half of wage profile. The analysis by educational level and by sector confirms the sticky floor effect. Finally correcting for endogenous self-selection in temporary contract slightly modifies the magnitude of wage gap, without changing the main patterns evidenced in the standard quantile regression.