Fuchs and Wößmann - this study is from 2006 so predates the modern academy programme. Whilst it does suggest that autonomy improves outcomes, it isn't actually linking that to curriculum content nor to the current National Curriculum.
Wößmann, Lϋdemann, Schϋtz and West - there are multiple versions of the same piece of research from this group but, again, before the current curriculum and the rise of academisation.
What we do have, relating directly to academisation, is evidence that shows:
- academic results in maintained schools are higher on average than in academies,
- disadvantaged pupils in particular do, on average, worse in academies than maintained schools,
- there is no improvement in Ofsted rating visible between academies and maintained schools,
- schools that join academy trusts after negative Ofsteds are less likely to improve as effectively or efficiently as maintained schools,
Given that the academisation experiment has had autonomy over staffing and curriculum content for years, yet not been shown to have any positive impact on the education of children, the fact that they are going to have to employ qualified teachers and fulfill the requirements of a curriculum should not at all be assumed to be a negative thing.