Nature of data
The statistics in this release are based on final international travel and migration counts. They relate to the number of passenger movements, rather than to the number of people – that is, the multiple movements of individual people during a given reference period are each counted separately.
Free online database
A large number of international travel and migration tables are available through Statistics NZ's Infoshare database (www.stats.govt.nz/infoshare), a free online tool that provides access to a range of time-series data. The international travel and migration subject can be found under Tourism on the Browse page of the database.
Changes in passenger type
Passenger type (overseas visitor, New Zealand-resident traveller, or permanent and long-term (PLT) migrant) is based on the time spent in and out of New Zealand, determined from past arrivals and departures of a person, and responses to questions on the arrival or departure card. Responses to the questions, and therefore the passenger type allocated, may be based on intentions. If a person's intentions change later during the trip, this passenger type may no longer be correct. For example, a person may come to New Zealand with the declared intention of settling permanently (PLT migrant), but in fact may return overseas after a few months (overseas visitor). Data users should recognise the limitations inherent in the information supplied by travellers.
Permit type
The determination of passenger type by Statistics NZ is independent of the permit type a person holds.
With the exception of New Zealand citizens, Australian citizens, and a small number of other people exempt under the Immigration Act 1987, everyone entering New Zealand is required to obtain a permit to remain in New Zealand. People already in New Zealand can apply for a permit renewal or a new permit of a different type. However, Statistics NZ only holds data on the permit type that an individual was given on arrival.
Sampling accuracy
The statistics for short-term passenger movements by country (that is, overseas visitor arrivals by country of last permanent residence, and New Zealand-resident departures by country of main destination) are derived from a systematic random sample taken each month from arrival and departure cards, and are therefore subject to sampling errors. However, total counts for arrivals and departures of overseas visitors and New Zealand residents are actual counts, which are not subject to sampling errors. Figures for PLT arrivals and departures are also actual counts and have no sampling errors.
New Zealand-resident short-term departures
The commentaries relating to New Zealand-resident short-term departures are based on data for the country of main destination – that is, the country where each departing person intended to spend most of their time while away from New Zealand.
Seasonally adjusted and trend series
The purpose of seasonally adjusting a time series is to measure and remove the varying seasonal components in the series (for example, there are more visitor arrivals during the New Zealand summer, due to the warmer weather and longer daylight hours). This makes the data for adjacent periods more comparable.
The seasonal adjustment process for international travel and migration statistics uses Statistics NZ's standard seasonal adjustment package, X-12-ARIMA, with enhancements which allow the specification and adjustment of additional calendar effects. These include the number and type of trading days in the month (as more people generally arrive and depart on Friday, Saturday, and Sunday), and holiday periods, which have important effects on travel but in different months each year (eg Easter can be in March or April).
Both monthly and quarterly seasonally adjusted series are available. The quarterly series are adjusted independently of the adjustments made to the monthly series. Hence, quarterly figures may not equal the sum of monthly seasonally adjusted figures.
Seasonally adjusted and trend data back to January 1996 are subject to revision each period. The size of these revisions is expected to be minimal, with the largest revisions occurring in the periods immediately before the current month or quarter. Data before January 1996 is not revised. This cut-off is used because of the change to a four-term school year in 1996, which resulted in changes to the seasonal patterns of the New Zealand-resident arrivals and departures series.
Processing system
The international travel and migration processing system incorporates scanning and image recognition technology. All arrival and departure cards are processed, but for around 9 in 10 cards the required information is captured automatically and no operator intervention is needed.
More information
For more information, follow the link from the technical notes of this release on the Statistics NZ website.
Copyright
Information obtained from Statistics NZ may be freely used, reproduced, or quoted unless otherwise specified. In all cases Statistics NZ must be acknowledged as the source.
Liability
While care has been used in processing, analysing, and extracting information, Statistics NZ gives no warranty that the information supplied is free from error. Statistics NZ shall not be liable for any loss suffered through the use, directly or indirectly, of any information, product, or service.
Timing
Timed statistical releases are delivered using postal and electronic services provided by third parties. Delivery of these releases may be delayed by circumstances outside the control of Statistics NZ. Statistics NZ accepts no responsibility for any such delays.