informal employment is not exclusive to lowproductivity sectors where of wage workers have no formal contract for of wage workers in medium and highproductivity sectors are also in that position moreover of male wage workers have formal contracts compared with of women although a slightly lower proportion of men have longterm contracts see table ii its variations are linked to the behaviour of human capital and patterns of productivity the competitiveness of the sectors providing the employment and the level of protection and negotiating power of workers which in turn is related to factors such as the degree of unionization and the possibility of collective bargaining