The ideal situation would be to use longitudinal data and fixed-effect panel regression methods to control for self-selection, cohort effects or other types of unobserved heterogeneity besides labour participation choices (Gangl and Ziefle, 2009). There has been an increase in the demand for places at childcare centres during recent years, and most of this has been met by the private sector. There is growing unmet demand for places at State-run day-care centres and kindergartens from those unable to pay for the care of their children.