Average funding costs for banks in New Zealand have increased by 170 basis points since the financial crisis in 2008, analysis by the Reserve Bank of New Zealand shows.An article in the RBNZ's quarterly Bulletin estimates the cost of funds over the last decade, measured as a spread to its targeted official cash rate.Over the six years to 2008, and before the demise of Lehman Brothers, banks could fund at an average rate of 60 basis points below the OCR.In the three and half years since then, this spread has averaged 110 basis points above the OCR.Taking a shorter term view, the RBNZ noted that funding costs have increased from "about the third quarter of last year as the European debt crisis developed.  "Our estimate as at the end of May for overall indicative marginal funding costs was about 130 basis points over the OCR," the RBNZ said. This is 20 bps more than the post-crisis average.