Quality Statement
Years since arrival in New Zealand is the number of completed years up to census night, since a person born overseas first arrived in New Zealand to live, irrespective of any intervening absences, whether temporary or long term.
High quality
Data quality processes section below has more detail on the rating.
Priority level 3
A priority level is assigned to all census concepts: priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).
Years since arrival in New Zealand is a priority 3 concept. Priority 3 concepts are given third priority in terms of quality, time, and resources across all phases of the census. Priority 3 concepts are those that have:
- data that census would not be solely run for, and information about population groups that could not be captured without being in a census
- data that is important to certain groups
- data that can be used to create sampling frames for other surveys.
The census priority level for years since arrival in New Zealand remains the same as 2018.
The 2023 Census: Final content report has more information on priority ratings for census concepts.
Overseas-born census usually resident population count
‘Subject population’ means the people, families, households, or dwellings that the variable applies to.
Years since arrival in New Zealand is classified into the following categories:
Census years since arrival in New Zealand V1.0.0 – level 1 of 2
| Code | Category |
|---|---|
| 00 | Less than one year |
| 01 | 1 year |
| 02 | 2 years |
| .... | ..... |
| 96 | 96 years |
| 97 | 97 years or more |
| 99 | Not elsewhere included |
Years since arrival in New Zealand uses a 2-level hierarchical classification with level 1 categories presented in the table above. Follow the link above the table to examine the classification in more detail.
‘Not elsewhere included’ includes the residual categories of ‘Response unidentifiable’, ‘Response outside scope’, and ‘Not stated’.
For many outputs the following classification is used:
The classification categorises single years until 4 years, then mixed groups (5-9 years and 10-19 years) up to ‘20 years or more’.
The 2023 Census classification for years since arrival in New Zealand is consistent with that used in 2018 Census.
Standards and classifications has more information on what classifications are, how they are reviewed, where they are stored, and how to provide feedback on them.
Years since arrival in New Zealand is derived from the month and year a respondent first arrived to live in New Zealand. This was collected on the individual form (question 10 paper form).
There were differences in the layout and the way a person could respond between the modes of collection (online and paper forms).
On the online form:
- built-in routing functionality directed individuals to the appropriate questions. If a respondent indicated they were born overseas, they were directed to the year of arrival question.
On the paper form:
- a respondent could leave the answer blank or provide a response outside the valid range. Blank responses were coded to ‘Not stated’, and responses outside the valid range were coded to ‘Response unidentifiable’
- those born in New Zealand could answer the year and month of arrival questions. These were filtered out by using the subject population.
Data from the online forms may therefore be of higher overall quality than data from paper forms. However, processing checks and edits were in place to improve the quality of the paper forms.
Stats NZ Store House has samples for both the individual and dwelling paper forms.
Data-use outside Stats NZ:
- used together with birthplace to develop, monitor, and evaluate settlement programmes for immigrants
- to understand the outcomes for both recent and long-term migrants
- to understand the distribution of migrants across New Zealand
- to provide information on immigration trends.
Data-use by Stats NZ:
- to capture changes in the social and economic status of immigrants.
Alternative data sources were used for missing and residual census responses and responses that could not be classified or did not provide the type of information asked for. The table below shows the distribution of data sources for years since arrival in New Zealand data.
| Data sources for years since arrival in New Zealand, as a percentage of overseas-born census usually resident population count, 2023 Census | ||
|---|---|---|
| Source of years since arrival in New Zealand data | Percent | |
| 2023 Census response | 77.2 | |
| Historical census | 6.8 | |
| 2018 Census | 5.4 | |
| 2013 Census | 1.4 | |
| Admin data | 15.2 | |
| Deterministic derivation | 0.0 | |
| Statistical imputation | 0.0 | |
| No information | 0.7 | |
| Total | 100.0 | |
| Note: Due to rounding, individual figures may not always sum to the stated total(s) or score contributions. | ||
Alternative data sourcing uses a combination of historical census and admin data. New Zealand Customs Service border movements are the most reliable admin source and are available for people arriving to New Zealand from 2000 onwards. Priority order for alternative data sources are as follows:
- 2018 Census (values greater than or equal to 18 years)
- 2013 Census (values greater than or equal to 13 years)
- New Zealand Customs Service border movements - using the earliest journey determined to be a permanent or long-term migration arrival
- 2018 Census (values less than 18 years)
- 2013 Census (values less than 13 years).
Editing, data sources, and imputation in the 2023 Census describes how data quality is improved by editing, and how missing and residual responses are filled with alternative data sources (admin data and historical census responses) or statistical imputation. This webpage also contains a spreadsheet that provides additional detail on the admin data sources.
Missing and residual responses represent data gaps where respondents either did not provide answers (missing responses) or provided answers that were not valid (residual responses).
Where possible, alternative data sources have been used to fill missing and residual responses in the 2023 and 2018 Censuses.
Percentage of ‘Not stated’ for the overseas-born census usually resident population count:
- 2023: 0.7 percent
- 2018: 1.3 percent
- 2013: 3.6 percent
For output purposes, the residual category responses are grouped with ‘Not stated’ and are classified as ‘Not elsewhere included’.
Percentage of ‘Not elsewhere included’ for the overseas-born census usually resident population count:
- 2023: 0.9 percent
- 2018: 1.4 percent
- 2013: 3.9 percent
Overall quality rating: High
Data has been evaluated to assess whether it meets quality standards and is suitable for use.
Three quality metrics contribute to the overall quality rating:
- data sources and coverage
- consistency and coherence
- accuracy of responses.
The lowest rated metric determines the overall quality rating.
Data quality assurance in the 2023 Census provides more information on the quality rating scale.
Data sources and coverage: Very high quality
The quality of all the data sources that contribute to the output for the variable were assessed. To calculate the data sources and coverage quality score for a variable, each data source is rated and multiplied by the proportion it contributes to the total output.
The rating for a valid census response is defined as 1.00. Ratings for other sources are the best estimates available of their quality relative to a census response. Each source that contributes to the output for that variable is then multiplied by the proportion it contributes to the total output. The total score then determines the metric rating according to the following range:
- 0.98–1.00 = very high
- 0.95–<0.98 = high
- 0.90–<0.95 = moderate
- 0.75–<0.90 = poor
- <0.75 = very poor.
The high proportion of data received from 2023 Census forms, alongside the high quality of alternative data sources, resulted in a score of 0.98, leading to the quality rating of very high.
| Data sources and coverage rating calculation for years since arrival in New Zealand, overseas-born census usually resident population count, 2023 Census | |||
|---|---|---|---|
| Source of years since arrival in New Zealand data | Rating | Percent | Score contribution |
| 2023 Census response | 1.00 | 77.22 | 0.77 |
| 2018 Census | 0.95 | 5.44 | 0.05 |
| 2013 Census | 0.88 | 1.38 | 0.01 |
| Admin data | 0.93 | 15.24 | 0.14 |
| No information | 0.00 | 0.73 | 0.00 |
| Total | 100.00 | 0.98 | |
| Note: Due to rounding, individual figures may not always sum to stated total(s) or score contributions. | |||
Consistency and coherence: Very high quality
Years since arrival in New Zealand data is highly consistent with expectations across all consistency checks.
Comparison with outcomes-based migration estimates show a clear consistency between census and migration data. While the migration data values are higher than census, census follows the migration patterns very closely.
Accuracy of responses: High quality
Years since arrival in New Zealand data has only minor data quality issues. The quality of coding and responses within classification categories is very high. Any issues with the variable appear in a very low number of cases (typically less than a hundred).
Improvements to scanning repair for paper form responses had a positive impact on accuracy and overall data quality. A small number of edits were needed for the years since arrival in New Zealand variable.
Years since arrival in New Zealand data can be used in a comparable manner to the 2018 and 2013 Censuses and it is recommended that data users familiarise themselves with the changes in methodology between each census.
When using this data, users should be aware that:
- Month and year of arrival are both used to derive years since arrival in New Zealand. Probabilistic imputation is used for month of arrival, when it is not available. Probabilistic imputation is also used for years since arrival in New Zealand when the month of arrival is March. In both instances, years since arrival in New Zealand data might be incorrect by one year.
- The count of individuals in the 1-2 years since arrival in New Zealand category is lower when compared with previous censuses. This change is consistent with expectations due to the border closure between 2020 and 2022.
Comparisons to other data sources
Although there are surveys and sources other than the census that collect years since arrival data, data users are advised to familiarise themselves with the strengths and limitations of the sources before use.
Key considerations when comparing years since arrival information from the 2023 Census with other sources include:
- Census is a key source of information on years since arrival in New Zealand for small areas and small populations. Many other sources do not provide detail at this level.
- Census aims to be a national count of all individuals in a population while other surveys (such as the Household Labour Force Survey and the General Social Survey) measuring this variable are only based on a sample of the population.
To assess how this concept aligns with the variables from previous censuses, use the links below:
- Years since arrival in New Zealand – 2018 Information by variable
- Years since arrival in New Zealand – 2013 Information by variable
Contact our Information centre for further information about using this concept.
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