Dr Andrew Leigh writes: Re. “Education and schooling: not the same thing” (6 October, item 10). On Friday, Charles Richardson criticised Craig Emerson’s proposal to raise the compulsory school leaving age in Australia, opining that “rising school leaving ages do not seem to have been correlated with higher educational achievement”. I’m not sure what evidence Charles has in mind. In a paper last year, Chris Ryan and I boss@crikey.com.au. Preference will be given to comments that are short and succinct: maximum length is 200 words (we reserve the right to edit comments for length). Please include your full name – we won’t publish comments anonymously unless there is a very good reason.