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Overseas Merchandise Trade: June 2015
Embargoed until 10:45am  –  24 July 2015
Data quality

Period-specific information
This section contains data information that has changed since the last release.

General information
This section contains information that does not change between releases.

Period-specific information

Number of working days

There were 21 working days in June 2015, compared with 20 in June 2014.

Foreign currency conversions – June 2015

Import values are converted from foreign currencies when import documents are processed by New Zealand Customs Service (NZCS).

We convert values given in foreign currencies into New Zealand dollars (NZD), using weekly exchange rates, when we compile the statistics.

 Currency conversions – June 2015
 Foreign currencies to New Zealand dollars

 Currency  Number of
 Value in
foreign currency
 Value in NZD
 Average exchange
 USD                        38,696  1,733 2,454      0.7062
 AUD    41,647    256    281      0.9141
 EUR      6,193    175    277      0.6328
 GBP      2,532      45    98      0.4557
 JPY      1,058 8,497    97 87.21
 Other currencies      2,123 ...     72 ...
 Total in foreign currency  92,249 ... 3,279 ...
 NZD   72,341 ...    952 ...
 Total 164,590 ... 4,231


 Symbol: ... not applicable

In June 2015, we converted 92,249 export line entries worth $3.3 billion into NZD.

See Merchandise trade – data source for more information on the use of exchange rates.

General information

Merchandise trade – data source

We obtain data from export and import entry documents lodged with NZCS. Once processed by NZCS, we receive this data. 

We convert export values given in foreign currencies into NZD, using weekly exchange rates when the statistics are compiled. For exports, a rise in the NZD has a downward influence on prices and, as a consequence, quantities and values reduce.

Import values are converted from foreign currencies when import documents are processed by NZCS. NZCS sets the exchange rates each fortnight. These rates are prepared 11 days before the start of the fortnight, so have a lag of 11 to 25 days compared with the daily rates published by the Reserve Bank. For imports, a rise in the NZD has a downward influence on prices and an upward influence on quantities. The combined influence on values can be either positive or negative.

Crude oil imports – effects of timing of recording

Imports are generally compiled by date-of-entry clearance by NZCS. NZCS entries are required from up to five days before, to 20 working days after, arrival of goods into New Zealand. The exception to this rule is for crude oil imports, which can have entries lodged later than 20 working days after entry into New Zealand.

We estimate crude oil values for the latest month using actual quantities and country-of-origin data (provided by NZCS, based on information from the refinery at Marsden Point), together with estimated prices. These estimates for crude oil are replaced once actual entries are lodged with NZCS.

While all entries are provisional for the latest three months, and have the potential to be changed by the importer/exporter within this period, changes are not common, and generally do not have a material impact on the results. However, New Zealand has only a few ships carrying crude oil arriving each month, and each ship represents a high proportion of the monthly total of imported crude oil. Any variation in the data for crude oil resulting from a later lodgement date can result in a significant revision to the value. Once we receive actual lodgements from NZCS, the value for crude oil can be regarded as robust.

Seasonally adjusted series

We calculate seasonally adjusted series monthly and for calendar quarters using X-13ARIMA-SEATS, which adjusts for outlying values and uses a centred moving average. The X-13ARIMA-SEATS package is an updated version of X-12-ARIMA, developed by the U.S. Census Bureau.

Seasonal adjustment removes the estimated impact of regular seasonal events, such as pre-Christmas purchasing, from time series. This makes the figures for adjacent periods more comparable. Seasonally adjusted figures are estimates and are subject to revision each period, with the largest changes generally occurring in the latest periods.

Seasonal adjustment in Statistics New Zealand has more information.

Trend series

Time series can be split into trend, seasonal, and irregular components. Seasonal adjustment removes the seasonal component, while trend estimation removes the seasonal and irregular components. Trend estimates reveal the underlying direction of movement in a series and are used to identify turning points.

We calculate the trend series using X-13ARIMA-SEATS. The length of the centred moving average is selected automatically and can be 9, 13, or 23 months, depending on the relative variability of the irregular component compared with the trend. A long moving average smoothes the trend series but slows the response to underlying changes in growth rates. A short moving average produces a trend series that is less smooth but quicker to identify turning points.

To improve estimation of the underlying movement, we calculate the imports trend after removing individual import items that have cif values of $100 million or more, such as large aircraft and ships. The trade balance trend is calculated by subtracting the imports trend from the exports trend.

We recalculate trend figures each month. Using new monthly data means that previously published trend estimates are revised. These revisions mainly affect the latest months and can be large if a trade value is initially treated as an outlier but is later found to be part of the underlying trend.

Broad economic category groups

Broad economic category (BEC) groups are arranged, as far as practicable, to align with the System of National Accounts’ three basic classes: capital goods, intermediate goods, and consumption goods. We categorise commodities in BEC groups on the basis of their main end use. This means, for example, that all video recorders are treated as consumption goods even though some are used in business. Similarly, all helicopters are treated as transport equipment even though some are military goods (and are treated as such in the national accounts).

New Zealand Harmonised System Classification

From January 2012, we compile overseas merchandise trade (OMT) data using the Harmonised System classification (HS2012). Before January 2012, HS2007 applies.

The classification change means data users need to take care when analysing time-series data, although changes from this review are not as significant as when HS2007 was introduced.

We will use HS2012 within OMT statistics until the next five-yearly review in 2017. Minor amendments may still occur on a quarterly basis.

Although the classification change potentially affects the published seasonally adjusted and trend series, our investigations so far show a negligible effect. We will communicate any effects we find when conducting our normal seasonal adjustment or trend series review processes.

HS2012 changes have been implemented in overseas trade indexes (OTI).

See Harmonised System 2012 and trade statistics for more information on how HS2012 has affected overseas merchandise trade data.

See Harmonised System 2012 for information about the HS2012 classification.

Standard International Trade Classification

The Standard International Trade Classification (SITC) is an output classification that uses Harmonised System (HS) codes at the six-digit level as building blocks. It was designed by the United Nations as an analytical tool for economic analysis, and includes some simple implications regarding level of processing. Published figures are at a high level of aggregation; more disaggregated information is available on Infoshare

Contact customer services at: for customised jobs using the SITC Rev 4 classification.

We compile OMT statistics in close accordance with the United Nations' International Merchandise Trade Statistics Concepts and Definitions. OMT data, after adjustment, is used in the balance of payments and national accounts. The adjustments are for coverage, timing, valuation, and classification. 

See New Zealand's international statistics: user guide (published 2015) for more explanation.

Confidential items

Under Section 37A (d) of the Statistics Act, the Government Statistician may disclose details of external trade, movement of ships, and cargo handled at ports. However, we understand that the release of merchandise trade commodity information can, in some cases, place commercially sensitive information in the public domain. We can provide a limited form of confidential status for commodity items (at the discretion of the Government Statistician), on application by a company or business.

In practice, all confidential HS codes are aggregated into the code 9809.00.00.00 to protect their confidentiality and to maintain total export and import values. Any aggregations of HS codes below this level, which encompass confidential 10-digit codes, exclude the confidential value(s) for these codes.

The only aggregates that include the confidential codes are total exports, total imports, and the total exports and imports by country.

More information

See more information about Overseas Merchandise Trade

Statistics in this release have been produced in accordance with the Official Statistics System principles and protocols for producers of Tier 1 statistics for quality. They conform to the Statistics NZ Methodological Standard for Reporting of Data Quality.


While all care and diligence has been used in processing, analysing, and extracting data and information in this publication, Statistics NZ gives no warranty it is error-free and will not be liable for any loss or damage suffered by the use directly, or indirectly, of the information in this publication.


Our information releases are delivered electronically by third parties. Delivery may be delayed by circumstances outside our control. Statistics NZ does not accept responsibility for any such delay.

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