Last night the New Zealand initiative hosted a debate about whether the government should ban university graduates from marrying each other, as a way to reduce inequality.

I’m not sure it was the most helpful way to approach inequality, as it’s an obviously ludicrous proposal. The affirmative team, from Victoria University, did a spirited job of arguing that since the government already only recognises marriages it thinks appropriate – you can’t marry a tree, for instance – it could legitimately extend that policy and not recognise marriages that increase inequality by concentrating high earners in certain households. But of course it wasn’t ultimately convincing, and anyway it completely misses the point about these issues.

(Incidentally it’d be great if people could stop airbrushing the politics out of this debate. Inequality did rise most sharply in the 1980s and 1990s, it’s true – the developed world’s biggest increase in inequality at that time – but the only reason it fell in the 2000s is because of specific government policies, notably Working for Families and the higher minimum wage. The Household Incomes Report is very clear on this. And since the GFC, income increases have been greater for the rich than for the poor, potentially counteracting the gains of the 2000s. Arguing that inequality just stopped rising 15 years ago elides all these important points.)

High-earning people marrying each other in greater numbers is of course a problem, because it widens inequality and – as the initiative’s head of research, Eric Crampton, alluded to afterwards – because it’s part of an increasingly segregated society in which people lose all sense of how the other half lives. We stop being able to understand how the country works and how people are getting on, we lose empathy for and trust in other people, and ultimately democracy stops working as it should.

But in a way high-earning people marrying each other is only a symptom of an already divided world. Divisions between rich and poor start very early, as kids grow up in neighbourhoods with concentrations of wealthy and poverty. That’ll get fixed with housing developments that mix state housing in with affordable and standard market homes – not with worrying about who’s marrying whom.

The other point missing from this debate was that the problem of these kinds of marriage would disappear if graduates didn’t earn so much more than people in trades. If aged care workers earned more and lawyers less, lawyers marrying lawyers would have minimal effect on inequality. And morally it’s hard to see why the earnings difference should be so big, except to compensate for the years of foregone income spent studying.

Aged care workers are important people, of equal moral worth to lawyers (or greater, in many cases). You can make arguments about the rarity and productivity of lawyers as against aged care workers, but people aren’t economic inputs, they’re people, and you can argue that their basic humanity and contribution to society is what should determine their pay. Now that’s a moot I would like to have seen debated.