The studies found that students' test scores are closely related to their socio-economic status (SES – a measure of a family's education, income and occupation). Once differences in SES are taken into account, there are no significant differences between the test results of private and public schools.

A study published by Flinders University academics concluded: "the observation that non-government schools achieve higher scores than government ones is not the result of an inherent higher quality of non-government schools. It is rather the result of the more privileged high SES students self-selecting into non-government schools and taking their existing advantage with them."

Meanwhile, other studies have shown that public school students perform better at university. Barbara Preston reported in The Conversation that "on average, graduates of state schools receive the same marks at the end of first-year university as students of private schools who had tertiary entrance scores around three to six points higher."

Further, University of Canberra researcher Jennifer Chester reports that, after controlling for other variables, there is no difference in employment rates or income levels between those educated in public and private schools.

This article appeared in ParentACTion, Term 4, 2014. See other past editions of our quarterly magazine.