No, Mr English, housing costs are not a key cause of inequality

A little while back, Finance Minister Bill English gave a speech in which he claimed that “poor urban planning is one of the significant drivers of inequality”. His logic is that bad urban planning drives up the cost of building new houses, limiting supply and thus causing rents to rise sharply and house prices to skyrocket. This effect is felt most strongly by the poor, who pay more of their income on housing costs, and so it widens income gaps.

Leaving aside whether urban planning is really to blame for the housing crisis, these claims are part of a wider government argument that housing is a key driver of inequality – an argument they make, sceptics would say, because it’s an area they happen to be taking action on already. Now, it’s true that, as English says, “the gap between incomes measured before housing costs and after housing costs is growing. Housing costs are becoming a larger proportion of incomes – and that matters the most at the bottom end of incomes among people who have few choices.” So it’s good to see the government recognising this fact.

But just because housing costs are making inequality worse doesn’t mean that they are the main driver, or even “significant”. Running the numbers on this, which I’ve just got around to doing, makes the point. The 2015 Household incomes in New Zealand report shows that in 1982, someone just on the edge of the poorest tenth of the country had housing costs of $4,200, on income post-tax of around $15,000.

By 2013, that same person had housing costs of $7,300 on around $17,700 of post-tax income. So housing costs are clearly a massive issue for poor people, consume a large chunk of their income, and have increased for them by around $3,000 in 30 years. (And, the maths show, have left poor people poorer than they were 30 years ago, despite all the promises of economic growth and so on.)

But housing costs have increased at the richer end a little bit as well, so in the end housing costs by 2013 were widening the rich-poor gap (that is, pulling the poor down more than they pull down the rich) by about $2,200 more than they did in 1982. (If that statement isn’t completely clear, well, there’s no simpler way to put it, sadly.) That’s housing’s contribution to increased inequality – $2,200. But in the same period, the overall rich-poor gap widened by nearly $21,000.

That implies that the increased housing cost contributed about one-tenth of the overall increase in inequality in the last 30 years – not nothing, but hardly enough to qualify housing in general – let alone poor urban planning, which is just one part of the housing issue – as “one of the significant drivers” of inequality.