The Reserve Bank of New Zealand has unveiled a new analysis of loan to income multiple data on mortgages showing around 40 per cent of new loans were written at multiples of over five times income over the last year, including around 60 per cent of loans to landlords.The Bank of England moved last year to limit banks' home lending so that no than 15 per cent of their mortgages were at loan to income multiples of more than 4.5 times. New Zealand's Treasury has recommended the Reserve Bank look at using loan to income multiple limits if the regulators' current loan to value ratio limits did not slow the Auckland housing market enough.The Reserve Bank published this analysis in its six-monthly Financial Stability Report, including a special 'Box C' section of the report's section on 'Financial Risks to the New Zealand economy.'The bank warned in the report of a growing risk of a sharp correction in house prices in Auckland, where annual house price inflation rose to 26 per cent in September and the house price to income multiple hit 9.2, up from 6.0 in 2011.The Reserve Bank limited high LVR lending (above 80 per cent) to no more than ten per cent of new lending in October 2013, which halved Auckland's annual house price inflation rate to 8.5 per cent in its first year. But the effect wore off and prices surged again from October 2014 after the National Government was re-elected and an Opposition proposal for a Capital Gains Tax was rejected. A surge in net migration to record highs through 2015 and a fall of more than 100 basis points in fixed mortgage rates to around 4.3 per cent also helped push Auckland house price inflation back over 20 per cent by mid 2015.In May the Reserve Bank announced a toughening of the high LVR limits in Auckland from November 1, limiting loans to landlords in Auckland with an LVR of over 70 per cent to ten per cent of new lending. The Government also launched a new capital gains tax test to catch investors flipping their properties within two years from October 1, and new reporting requirements for non-resident investors.Real Estate Institute figures for October were released this week. They showed Auckland house sales volumes fell 19.4 per cent in October from September and the median price fell 3.0 per cent in the month to NZ$748,250. Reserve Bank Governor Graeme Wheeler said the Reserve Bank had no current plans to introduce British-style limits on loan to income multiples or limits on loan affordability, as was suggested by Treasury and the IMF if the new LVR limits did not work."At this point we are not considering anything in respect of debt to income ratios," Wheeler told a news conference after the release of the report."We are looking at the experience in other countries. There are issues around standardisation of data, for example, between banks," he said."But in essence, we really want to see how the current