However, there is a motherhood wage penalty in the case of informal workers, the predicted natural log of the hourly wage is 1.15 pesos for non-mothers and 0.98 pesos for mothers. The positive wage gap of 0.16 in favour of nonmothers is significant, and almost the entire difference (75%) is significantly unexplained or associated with possible discrimination. Thus, these findings bear out the original hypothesis of a motherhood wage penalty in the informal sector, and most of this penalty is attributable to discrimination or unobserved factors.17 It is also worth noting that this 0.16 differential in the informal sector is at the upper end of the distribution of the motherhood wage penalty estimates reported above.