One of the headline pledges in Labour's newly-launched manifesto is to scrap tuition fees. This has attracted a lot of scoffing, as the twitterati noted that it effectively creates yet another middle-class subsidy paid for out of general taxation.

The detractors are entirely right, as far as their arguments go. Yet I wonder if there is not something of a contrarian case to be made for Jeremy Corbyn's latest brainwave.

I have written previously on the problems of excessive healthcare consumption, and how it costs enormous sums of money for minimal net health benefits.

Higher education is a similar good. It is something that people want to consume a lot of, and, given the chance, they do. This is not something to be celebrated, because, just as with healthcare, most do not benefit, though at least in the case of higher education there are is a clearly defined sub-population that actually does - the most intellectually able.

There is, of course, a substantial graduate wage premium. The question is whether that premium reflects skills that graduates acquire at university or their own natural talents.

It is well known that graduates tend to be somewhat smarter, more diligent, and more prosocial than the average non-graduate (how do you think they got the grades necessary to get into university at all?) University degrees may be largely value-free in their own right, but serve a useful function as honest signals of these traits.

In the economics literature, these two competing models are known as the "human capital" and "signalling" models of education, respectively. They are not, of course, mutually exclusive; both can be true at the same time.

The graduate wage premium may well be part human capital and part signalling, to a greater or lesser degree across times and nations. It certainly seems to be the case that high-ability students do in fact tend to acquire some genuinely useful knowledge at university for which they are genuinely rewarded by the labour market. Consequently, a "100% signalling" model of education is very unlikely to be true.

This opens up room for debate over the correct percentage of people who actually do need to go to university. If, for the majority, the benefits they accrue are all due to signalling, they very likely do not need three years of solid drinking - in addition to £40,000 worth of student debt - in order to signal their positive traits to potential employers.

The costs of higher education run beyond the damage to internal organs and finances. High levels of student debt are well known to negatively impact family formation and impede childbearing. This is partly because students tend not to get pregnant, and also because of the stress of the direct financial burden.

The biggest problem, however, is that tuition fees dramatically raise the expected cost of each child, and couples planning their family size do not fail to take this into account. Of course, if the smarter part of the population does not reproduce in sufficient numbers, overall population cognitive ability is likely to decline in the long term.

Historically, in the age of free university places, a far lower percentage of students went to university, and given the parlous state of the public finances and the rising costs of higher education, it seems fairly unlikely that a government committed to funding free higher education would be able to cover the costs of the current numbers.

It would very likely have to introduce rationing. Just like how central government funding of the NHS keeps healthcare spending down and focuses it on the absolute necessary minimums, central government funding of education would likely serve to control cost disease in higher education, leading to cutbacks in administration and facilities spending.

Obviously, if healthcare and higher education were genuinely valuable in their own right, the central government model of chronic underfunding would be a disaster. In reality, however, it seems as though high demand for healthcare spending largely emerges out our evolved propensity to signal prosociality, and because of various cognitive biases which make it hard to spot the costs of excessive interventions (unless, of course, you are a funeral director and the doctors go on strike).

High demand for higher education is largely the product of a seemingly endless and wholly unproductive signalling arms race, one which no one can avoid and is genuinely beneficial for the winners, but enormously wasteful overall.

It may, of course, be the case that having acquired a taste for mass higher education, the great British public would simply not accept a reversion to much lower higher education participation rates, and abolishing tuition fees would only serve to make a bad situation worse. In theory, however, the idea is a good one.

Subsidising the cognitive elite to acquire skills and have children is not exactly egalitarian policymaking, and that may make it a tough sell. On the grounds of prudence, though, it might be worth a shot.