The benefits are significant for disadvantaged pupils (e.g. Blau and Currie, 2006). According to PISA, native-born children of immigrants who attended pre-primary school are a full year ahead of their peers who stayed at home, in terms of reading skills. Recognising this, the provision of cost-effective and quality childhood education and care has been on the government's agenda in many OECD countries (Box 3.2). These efforts can be continued. Only a few OECD countries, notably New Zealand, Norway and Sweden have established such an integrated ECEC system under one lead ministry which provides continuous development for pre-school children. The integration of care and education under the Ministry of Education influenced the style of curriculum that was developed.