3The EU-SILC 2013 child-specific material deprivation module is optional, hence the number of countries analysed is limited. The children who are left behind, also referred to as the poorest children, or the children in the bottom end of the income distribution, are those in the poorest decile, i.e. with incomes falling below the 10th percentile in each country. This includes inter-EU migrants as well as those born outside the Union.