In one of the most trenchant contributions to the apprenticeship debate in the Commons last month, shadow skills minister Gordon Marsden posed the question, “What are apprenticeships for?” It is the same question that the Association of Employment and Learning Providers asked in a policy paper in the same month. Clearly, lots of people want an answer.

Normally, one would want questions like this settled before spending #163;1.4 billion. But, in fact, it is this growth in apprenticeship spending, particularly for adults, that has prompted the question. While it was once clear what apprenticeships were for - they were the best way for young people to make a start in the world of work while gaining qualifications - now it is not.

The announcement by skills minister John Hayes that all 16-19 apprenticeships will have to last at least 12 months was intended to protect standards in the flagship vocational qualification. But exempting apprenticeships for those aged 19 and over risks increasing the confusion and uncertainty about what makes an apprentice.

If employers really value apprentices, why do they not hire them as such, rather than employing them, perhaps for years, and then ramming them through a crash course?

Until recently, adult apprentices formed only a tiny fraction of the whole. So when research established that apprenticeships had a huge impact on future earnings and employment prospects, it was based primarily on young people who had only just started in work. No one has much of an idea of the benefit of awarding qualifications to people who already know how to do their jobs.

Is the value of an apprenticeship in achieving the accreditation, in which case it is fine for someone to be an employee for a substantial period of time and then quickly fulfil the assessment criteria? Or is the value in having a prolonged period of work and training during which your employer is invested in your learning and development, and where all sorts of informal learning takes place? In this case, simply converting to an apprenticeship late in the day cannot possibly replicate that impact.

Perhaps research will later prove that the work-first, assess-later model is just as good as a traditional apprenticeship. Perhaps it will not. But for now, these are questions that the government is not very interested in answering. Because for all its criticism of Labour’s obsession with targets, the coalition’s prime purpose in apprenticeships is to win a numbers game, providing Mr Hayes with ever larger figures to triumphantly announce and giving the subliminal impression that something is being done about youth unemployment. That is one answer to the question of what apprenticeships are for, but not perhaps the one we hoped for.