Usual residence one year ago (information about this variable and its quality)

Priority level

Priority level 2

We assign a priority level to all census variables: Priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).

Usual residence one year ago is a priority 2 variable. Priority 2 variables cover key subject populations that are important for policy development, evaluation, or monitoring. These variables are given second priority in terms of quality, time, and resources across all phases of a census.

Usual residence one year ago has not been included as a question on the census form since 1981.

Quality Management Strategy has more information on the priority rating.

Overall quality rating for 2018 Census

Poor quality

Data quality processes section below has more detail on the rating for this variable.

Caution is advised when using this variable at small geographies. Please see Recommendations for use and further information section below.

The External Data Quality Panel has commented on the quality of this variable. Final report of the 2018 Census External Data Quality Panel has more information.

Subject population

Census usually resident population

‘Subject population’ means the people, families, households, or dwellings to whom the variable applies.

How this data is classified

Usual Residence 1 Year Ago Classification V2.0.0

Usual residence one year ago is a flat classification showing the meshblock of a respondent’s usual residence one year ago.

The usual residence one year ago address classification consists of a combination of classifications that are ordinarily stored independently of each other. There is a hierarchic relationship between the New Zealand geographic classifications of meshblock, statistical area 2 (SA2s), territorial authority (TA) and regional council (RC). For example, SA2s aggregate to form both TAs and RCs. The categories of each of these ordinarily independent classifications sit alongside each other at the same level of this classification. The country classification also sits alongside the New Zealand statistical standard of geographic areas, at the same level of usual residence one year ago classification.

The standard codes are:

Meshblock codes (7 digits)

SA2 codes (6 digits) prefixed by '9'

TA codes (3 digits) prefixed by '9999'

RC codes (2 digits) prefixed by '99999'

Country codes (4 digits) prefixed by '999'

9999977 Response unidentifiable

9999988 Response outside scope

9999995 Not born 1 year ago

9999996 No fixed abode

9999997 Country not stated

9999998 New Zealand not further defined

9999999 Not stated

The Standards and Classifications page provides background information on classifications and standards.

Usual Residence 1 Year Ago Indicator Classification V2.0.0

Usual residence one year ago indicator code is also a flat classification.

01 Same as usual residence

02 Elsewhere in New Zealand

03 Not born one year ago

04 Overseas

05 No fixed abode one year ago

77 Response unidentifiable

98 New Zealand not further defined

99 Not stated

‘Response unidentifiable’, ‘New Zealand not further defined’, and ‘Not stated’ can be grouped together for the ‘Not elsewhere included’ residual category.

Census Usual Residence One Year Ago Summary V1.0.0

Usual residence one year ago summary code, another flat classification, is used to show the differences between usual residence and usual residence one year ago for each respondent. This summary is derived from ‘usual residence’ and ‘usual residence one year ago’ information on the Census Individual Form.

01 Same usual residence as 1 year ago

02 Same territorial authority

03 Same regional council, different territorial authority/ territorial authority unknown

04 Different regional council, same island

05 Different regional council, different island

06 Area outside regional council/territorial authority stated but regional council not further defined/area outside territorial authority

07 No fixed abode 1 year ago

08 Overseas 1 year ago

09 Not born 1 year ago

97 Response unidentifiable

98 New Zealand not further defined

99 Not stated

‘Response unidentifiable’, ‘New Zealand not further defined’, and ‘Not stated’ can be grouped together for the ‘not elsewhere included’ residual category.

Question format

Usual residence one year ago address and indicator variables are collected on the online individual form and question 14 on the individual paper form.

Usual residence one year ago summary code is derived from the relationship between these variables and a respondent’s usual residence address.

On paper, people ticked a box to indicate that one year ago, they were ‘at their usual residence’, ‘at another address’, or ‘overseas’.

• If they chose ‘at another address’, they were required to write in that address.
• If they selected ‘overseas’, they were asked to provide the name of the country where they usually lived one year ago.

Online, the individual form was automatically populated with the respondent’s usual address from the household set up form. The respondent was then asked to confirm if they lived there one year ago. If they did not live there and instead selected ‘at another New Zealand address’, they were required to then enter that address. If they selected ‘I lived overseas 1 year ago’, they were asked to enter the country name.

Not born one year ago

• On paper, parents or caregivers of children aged less than one year could tick a box for ‘not born 1 year ago’.
• Online, parents were not required to answer the question because the response was coded to ‘not born 1 year ago’ during processing based on the age.

Stats NZ Store House has samples for both the individual and dwelling paper forms.

How this data is used

Outside Stats NZ

• Understanding population mobility within a region.
• Supporting long-term service planning (eg housing and transport planning, public health planning).

Within Stats NZ

• Improving the quality of Tier 1 statistics, eg population estimates.
• Measuring internal migration.
• Understanding regional population fluctuations.

2018 data sources

We used alternative data sources for missing census responses and responses that could not be classified or did not provide the type of information asked for. Where possible, we used responses from the 2013 Census, administrative data from the Integrated Data Infrastructure (IDI), or imputation.

The table below shows the breakdown of the various data sources used for this variable.

Administrative data was only used for admin enumerated individuals aged less than one year old who we also coded to ‘not born one year ago’. We could not categorise ‘usual residence one year ago’ for admin enumerated individuals aged over one year. These records are in the ‘no information’ category.

We used the IDI to source the age of admin enumerated individuals on census night. The IDI's sources include:

• Department of Internal Affairs
• Stats NZ
• Ministry of Education
• Ministry of Social Development
• Inland Revenue Department
• Ministry of Business, Innovation, and Employment
• Accident Compensation Corporation
• Ministry of Justice
• New Zealand Transport Authority
• Oranga Tamariki.

Missing and residual responses

‘No information’ in the data sources table above, is the percentage of the subject population coded to ‘not stated’.

For this variable, the percentage of responses with no information is high. There were no alternative data sources unless the respondent was aged less than one year and so could be coded to ‘not born one year ago’.

Percentage of ‘no information’ for the census usually resident population

• 2018: 15.2 percent.

Responses that could not be classified or did not provide the type of information asked for (coded to ‘Response unidentifiable’ and ‘New Zealand not further defined') remain in the data. These residuals are included in the ‘Response from 2018 Census’ percentage in the data sources table above.

For the ‘usual residence one year ago indicator’ and ‘usual residence one year ago summary’ variables, these residual category responses are grouped with ‘not stated’ and are classified as ‘not elsewhere included’.

Percentage of ‘not elsewhere included’ for the census usually resident population

• 2018: 16.8 percent.

Data quality processes

Overall quality rating: Poor quality

Data was evaluated to assess whether it meets quality standards and is suitable for use.

Three quality metrics contributed to the overall quality rating:

• data sources and coverage
• consistency and coherence
• data quality.

The lowest rated metric determines the overall quality rating.

Data quality assurance for 2018 Census provides more information on the quality rating scale.

Data sources and coverage: Poor quality

We have assessed the quality of all the data sources that contribute to the output for the variable. To calculate a 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:

• 98–100 = very high
• 95–<98 = high
• 90–<95 = moderate
• 75–<90 = poor
• <75 = very poor.

For usual residence one year ago, the small proportion of admin data and the high non-response rate contributed to the score of 0.85, determining the poor quality rating.

Consistency and coherence: High quality

As this question has not been asked since 1981, there is no 2006 or 2013 Census data to use for comparison. In recent censuses, information has only been collected on ‘usual residence five years ago’ and ‘years at usual residence’. Trends found in the ‘usual residence five years ago’ variable were consistent with the ‘usual residence one year ago’ trends.

Data quality: High quality

The usual residence once year ago data was checked for consistency within the dataset and included cross-tabulations to regional council level. The data has only minor data quality issues. The quality of coding and responses within classification categories is high. Any issues with the variable appear in a low number of cases.

Recommendations for use and further information

While the final quality rating for the data is poor due to the low response rate, the data quality and the consistency with expectations is good. This means the data can be used with some caution as a measure of internal mobility.

When using this data you should be aware that:

• due to the high percentage of missing data, we recommend using proportions rather than absolute counts, with the total stated as the denominator
• data has been assessed to be consistent with expectations at the regional council level of geography
• when using 'usual residence one year ago indicator' at small geographies, there will be variability in the percentage of missing data for a given area. This means some small geography areas will have poorer quality data than the overall quality rating.
• the percentage of data for which there is no information will differ for specific population groups from that of the overall usually resident population
• ‘usual residence one year ago’ has not been asked as a question on the individual form since 1981 so there is no timeseries for this variable.

Contact our Information Centre for further information about using this variable