This report sets out the latest internationally comparable data on child deprivation and relative child poverty. Taken together, these two different measures offer the best currently available picture of child poverty across the world's wealthiest nations. Previous reports in this series have shown that failure to protect children from poverty is one of the most costly mistakes a society can make. The heaviest cost of all is borne by the children themselves. But their nations must also pay a very significant price -- in reduced skills and productivity, in lower levels of health and educational achievement, in increased likelihood of unemployment and welfare dependence, in the higher costs of judicial and social protection systems, and in the loss of social cohesion. [Support for this report was provided by the Andorran, Belgian, Swiss and United Kingdom National Committees for UNICEF.]