https://phys.org/news/2018-06-immigrant-disadvantaged-children-benefit-early.html

The study, which looked at German school entry exam data, also shows that immigrant children and children from disadvantaged backgrounds are less likely to attend childcare at age three. The research will be published in the forthcoming Journal of Political Economy.

"Attending universal childcare from age three nearly eliminates the difference between immigrant and native children, when it comes to readiness for school. Yet, despite this clear educational benefit, children from immigrant and disadvantaged backgrounds, are substantially less likely to enter early childcare," said study co-author Professor Christian Dustmann, Director of CReAM (UCL Economics).