A large part of the wage differential between regular and non-regular workers can be attributed to differences in human capital and productivity. In particular, employment status, tenure, level of educational attainment, and demographic factors are shown to be the main factors affecting the wage gap. The discriminative wage gap between regular and non-regular workers decreases with smaller firm size. The regular workers are disadvantageous in terms of wage compared to their non-regular counterparts in firms with less than 10 workers.