Fuelled by federal stimuli of 440 million Swiss francs, the staggered expansion of
childcare in many cantons allows the evaluation of this family policy on female labour
supply. With new cantonal data, this study analyses both the decision to participate in
the labour market and the intensity of participation. Empirical results of difference-indifferences
regressions show that mothers who live in cantons that have expanded
their childcare services more than the national average work at higher percentage
rates. The reform stimulated part-time employment of between 20 and 36 hours per
week by 2 percentage points. The expansion of childcare particularly affected women
with two children and upper-secondary education, who are married or cohabit with their
partner.