As the Reserve Bank prepares to review the Official Cash Rate this week, commentators believe contradictory financial information mean the decision poses some difficulties for the bank.
Officials at the bank are faced with a stronger domestic economy and rising inflation at home against slowing global economic activity and concerns about debt mountains in Europe and the US.
While the announcement on Thursday is expected to leave the cost of borrowing unchanged at 2.5%, financial markets are pricing in a 70% chance of an increase by September.
The BNZ is predicting rises in September and October reflecting stronger-than-expected growth and reversing a cut in the rate to cushion the economy following the February earthquake. The OCR was previously 3%.
Westpac Bank chief economist Dominick Stephens says domestic conditions support the case for raising the cost of borrowing.
However, he predicts that the Reserve Bank will not move until December in the light of the higher New Zealand dollar, cooling commodity prices and slowdowns in two of New Zealand's main trading markets, Australia and China.