This paper sets out technical research and modelling improvements undertaken by NSW Treasury subsequent to the publication of the IGR. Most importantly, the methodology set out in this paper enables the estimation of the impact of policy measures that have a demonstrated effect on women’s labour market outcomes, specifically, measures that increase the affordability, availability and quality of early childhood education and care (ECEC). The research and methods set out in this paper underpin estimates of both long-term economic impacts and long-term revenue impacts of successful policy intervention that boosts labour market outcomes for women with young children.