This data records the changes in the weights of different currencies in the Trade Weighted Index over time.
The trade weighted index (TWI) is a weighted average of the New Zealand dollar with the currencies of New Zealand's major trading partners. We currently publish two TWIs:
Annually.
Weights are calculated annually in mid-December.
The statistics release calendar provides a long-term plan of scheduled releases. We update and release it on the first working day of the month.
View the statistics release calendar
Provisional data are italicised. Data are deemed provisional when a series is under review. New data, or revised data, are in bold font. This applies to the summary table only and not Excel files. We generally publish revisions when we update and release a new table. Should we need to make revisions more promptly, we post a note on the website. We also post any major changes in methodology as a note.
Information about the TWI and the method used to calculate the weights can be found in the following Bulletin articles:
We publish the TWI daily in B1 Exchange rates.
Weights for the TWI are calculated annually and published in tables B10 and B13.
The scale factor is calculated to prevent spurious shifts in the TWI that could otherwise occur as a result of the reweighting. By convention, the rescaling is done using the exchange rates prevailing at 11:10am on the day before the new weights are released. The new scale factor is set so that the TWI with the old weights is equal to the TWI with the new weights at that point in time.
There are 17 currencies included in the official TWI:
The base exchange rates as at 31 October 2014:
A new methodology was introduced for the official TWI in December 2014. The weights were backdated to 1984.
Weights for the reference year are calculated using finalised June year trade data from the previous year (for example, weights for 2015 were calculated from year ended June 2014 trade data).
From 1983 to 2014, the historical TWI weights were calculated using five currencies:
From 1979 to 1998, the weights were calculated solely on bilateral trade. Between 1999 and 2014, the weights were calculated using bilateral trade (50%) and the relative size (GDP) of the trading partner's economy (50%). Since 2014, the historical weights have been calculated using the 17 currencies included in the official TWI. The weights are based on bilateral trade.
Symbol or convention | Definition |
---|---|
0 | Zero or value rounded to zero |
- | Not applicable |
.. | Not available |
bold | Revised/new |
italics | Provisional |
Light grey background | Historical |
View our other Exchange and interest rate statistics series.