Do additional resources devoted to education improve students' learning outcomes, as parents, students and educationists tend to believe? Why is there a continuing controversy among educational economists as to whether resources matter? In The Resourcing Puzzle, Rosalind Levacic discusses how this controversy has arisen from the methodological problems of establishing causal relationships between social phenomena. She reviews evidence from recent good quality UK studies and discusses current research at the Institute of Education, University of London. Using the better quality English data now available, she investigates the relationship between school resources and attainment at Key Stage 3. Finally, Professor Levacic suggests how we may make further progress with research in this field and the use of evidence from it to inform policy making.