"Lower oil prices boost aggregate demand by improving household and firms' purchasing power due to more favourable terms of trade."
OPEC nations decided to maintain their level of supply last year in the face of falling prices as US production grew rapidly with technological advances, such as hydraulic fracturing, reducing the cost of extracting oil and gas in the world's biggest economy.
The US has traditionally been a net importer of oil, but since the advent of fracking, it's likely to be a net exporter in the foreseeable future.
New Zealand's central bank today kept its key rate on hold, and took rate hikes off its forecast horizon out to March 2017 due to the lower inflation track, which stemmed in large part from cheap oil.
"World oil prices are about 50 per cent below their June 2014 peak, more reflecting increased supply than demand factors," Governor Graeme Wheeler said.
"The fall in oil prices is net positive for global economic growth, but will further reduce inflation in the near term, at a tie when global inflation is already very low."
The Reserve Bank said it's allowed to look through the short-term effects on inflation by the slump in oil prices, which represent a one-off change.
However, if that feeds into broader changes in the way firms set prices and wages, or oil prices continue to side, the bank will likely be forced to cut interest rates.