How governments should direct money to families with children seems to be a constant part of the political and policy debate. The present government has made many changes to the structure of financial support to families with children, culminating in the child tax credit and working tax credit, perhaps the most radical reform in this area since child benefit replaced family allowance in the late 1970s. This research set out to improve our understanding of the way successive UK governments' have financially supported parents, the Joseph Rowntree Foundation has kindly supported the IFS in an analysis of how child-contingent support has changed since 1975, and how this relates to changes to taxes and benefits, the characteristics of households with children, and the costs of children.