"We suppose that women (couples), who are less than 40 years old, are faced with three types of sequential decisions: the fertility decision, the decision relative to the number of children to have and the decision concerning labour force participation.... We use a nested polychotomous discrete choice model to estimate the responsiveness of the behaviour of 'married' women in Quebec to variations in the expected flow of revenue resulting from changes in the parameters of the personal income tax and in the level of public monetary transfers conditional on the number of children. The model is estimated with micro-data from 9 repeated cross-sections for the years 1975 to 1987 with a full information maximum likelihood method.... This empirical setting is used to simulate the effects of changes made to the fiscal and transfer policies in favor of families with dependent children on fertility, [women's] labor force participation and the importance of spending costs for the two levels of government." (SUMMARY IN ENG)