According to the report schools which did less well often showed "a lack of clarity about the intended impact of the spending", did not monitor the effect properly and often spent the cash "indiscriminately on teaching assistants".
For instance curricula reforms have not always taken into account the books and instructional materials, teachers, teaching processes and assessment methods required to give them effect.
The most fundamental one remains the Baumol effect: labour-intensive services, such as nursing and teaching, have thus far proved as immune to productivity-enhancing technology as string quartets.