Retail and business interest rates still look pretty inflexible in New Zealand, with few lenders making a move yesterday to reduce interest rates on either assets or liabilities in the wake of the decision by the Reserve Bank of New Zealand to reduce the official cash rate target by half a percentage point to 7.5 per cent.The quarter of a percentage point cut in the cash rate in July produced virtually no reduction in interest rates paid, though that cut, at the time, seemed as much as anything to be about restraining banks from lifting rates (and, by implication, tolerating an effective widening of bank margins).In its quarterly statement on monetary policy, published yesterday, the RBNZ noted that while there was a decline in two-year fixed rates over the last two months, "the pass through into longer-term fixed rates and floating rates has been more limited".Next to non-existent might be a better way to put it. Almost no lender cut floating rate home loan rates. And no lender of note (and possibly no lender at all) cut rates on credit cards or on other variable rate loan products since July.Customers may wonder how much difference the cut in the cash rate this time may make.Three banks did announce corresponding cuts of 50 basis points in floating rate home loans: ASB, Bank of New Zealand and Kiwibank. AMP Home Loans and NZ Home loans also cut mortgage rates, as did Sovereign (a brand of ASB), according to Interest.co.nz.The RBNZ noted that wholesale funding costs were a restraint on any bank repricing of customer interest rates.Alan Bollard, the RBNZ governor, made it clear in an interview with Bloomberg that yesterday's interest-rate cut "was intended to ensure that banks do have room to cut rates …. We're keen to get some of the impact of this 50 basis points through to lower mortgage rates."