“…Available research on the underlying causes of the Matthew effect puts forward both macro-level supply-side and micro-level demand-side factors as complementary explanations for socio-economic gradients in formal childcare uptake. With respect to macro-level explanations, most contributions rely on variation in formal childcare setups between countries (Fuller and Liang, 1996;Krapf, 2014;Pavolini and Van Lancker, 2018;Van Lancker and Ghysels, 2016;Van Lancker, 2017), regions, neighbourhoods (Abrassart and Bonoli, 2015;Fuller and Liang, 1996;Hirshberg et al, 2005;Maes et al, 2023) or time periods (Vandenbroeck et al, 2014;Van Lancker, 2017) to assess the impact of policy design features on social inequality in formal childcare uptake. This approach has highlighted supply-side factors moderating social differentiation in formal childcare uptake, such as the affordability and the fee structure (Abrassart and Bonoli, 2015;Huston et al, 2002;Hirshberg et al, 2005;Pavolini and Van Lancker, 2018), accessibility (Pavolini and Van Lancker, 2018), priority criteria (European Commission, 2014), government spending levels (Van Lancker and Ghysels, 2016;Van Lancker, 2017), or policy coherence (Krapf, 2014).…”