There's a saying in physics that nature abhors a vacuum. That saying is even more true at the point where economics meets politics. Without hard data, a debate about policy can slide off into dangerous places that lead to bad decisions.
We're at that point with foreign ownership of homes in Auckland.
The Labour, Green and New Zealand First parties will all campaign on the need to restrict or block non-resident purchases of homes and land, saying it is inflating prices beyond the reach of young New Zealanders and forcing everyone else to pay higher interest rates and cope with a high New Zealand dollar.
The Government's response is that there's not much evidence to say there is a problem.
This month's BNZ-Real Estate Institute survey of estate agents found they thought 6.4 per cent of homes were bought by non-residents and about 25 per cent of the non-resident purchasers were from China. Hence, the implication is that "just" 1.6 per cent of buyers are from China.