Some central bankers might rather enjoy being mobbed by Japanese housewives. But Alan Bollard, governor of the Reserve Bank of New Zealand, may live to regret getting in the way of Japan's currency day-traders. Whether the RBNZ makes money on yesterday's currency intervention or not, it is a hard policy to justify in a small, open economy such as New Zealand's.

The central bank's sales of kiwi dollars drove the currency down by about 2 per cent against the yen and the US dollar. The RBNZ is trying to do something about the unwanted strength of the kiwi, which hit a 22-year high against the greenback earlier this month, a level that causes suffering for New Zealand's non-farm exporters.