An integrated approach that focuses on interventions in health, nutrition, water and sanitation, protection, and learning during the first years of children's lives can set a firm foundation for their entire lifetime. Given this commitment, they need consistently updated data on who is poor and how they are poor in order to monitor progress, identify gaps and guide policies and programmes - all in the interest of making sure that vulnerable children are not left behind. Multidimensional child poverty measures give a fuller picture of how children experience poverty.