Almost one in 10 houses in Auckland change hands within a year, a much higher turnover rate than the rest of New Zealand.
Figures supplied to the Weekend Herald by property data company CoreLogic show 8 per cent of homes in Auckland have been sold within 12 months of purchase in the year to date, compared to only 3 per cent for the rest of New Zealand.
Within six months, 3.6 per cent of Auckland homes were sold again, compared with 1 per cent in the rest of the country.
Repeat sales within a short time period are seen as an indicator of speculation, as buyers sell and resell multiple properties for capital gain.
Prime Minister John Key this week announced a possible land tax on foreign buyers to deter speculation in the Auckland property market, where the median price rose $70,000 in a month to $820,000 in March.
CoreLogic research analyst Nick Goodall said experience in Australia, which had similar taxes, was that foreign buyers would regard the tax as a cost of doing business.
It was also debatable whether foreign buyers drove prices up, even if they turned out to be a major portion of the market. Past experience showed first-home buyers paid the highest prices as they were more emotionally attached to a property, whereas investors would only pay a price which gave them a good financial return.
Meanwhile Wellington's deputy mayor Justin Lester has a simple solution for Aucklanders worried about the rising cost of housing in their city - move to the capital.
"If you're living in South Auckland and ... earning $50,000, and you can come down here and get the same job and probably be better paid, and you don't have the costs of commuting ...
"Sure there's a difference of two or three degrees in the weather but if you can sell up there and move down here and you've got two or three hundred thousand dollars in the bank - financially, why wouldn't you?"
Mr Lester said the price gap between Auckland and Wellington used to be about 25 per cent but was now 40 to 50 per cent.