Looking just at school education, the average expenditure per student across OECD countries increased by no less than 17% between 2005 and 2013 in constant prices (OECD, 2016). But over roughly the same period, the Programme for International Student Assessment (PISA) data from the 2003 and 2012 surveys show no significant improvement in test scores. Instead, in most countries the percentage of top performers has declined.