Subnational family and household projections
This release contains 2006-base family and household projections for the 16 regional council and 73 territorial authority areas of New Zealand. These supersede the subnational family and household projections 2001-base update released in October 2005. The projections have as a base the estimated resident population, estimated families, and estimated households of each area at 30 June 2006, and cover the period to 2031 at five-year intervals.
The projections are neither predictions nor forecasts. They provide an indication of possible future changes in the number and composition of families and households in subnational areas. While projection assumptions are formulated from an assessment of short-term and long-term demographic trends, there is no certainty that any of the assumptions will be realised. Therefore, Statistics New Zealand makes no judgement on the relative merits of the projected changes.
Household numbers should not be confused with building activity or dwelling numbers. 'Households' refers to private dwellings that are usually occupied by a person or group of people. Households therefore exclude non-private dwellings, unoccupied dwellings, and dwellings which are not the usual residence of people (eg holiday homes, second homes).
What has changed from the previous 2001-base projections?
Subnational family and household projections are updated every two to three years. These latest projections have been updated to incorporate the latest national family and household projections and subnational population projections. In turn, these are consistent with the latest national population projections (released 24 October 2007). Mid-range series 5 of the latest national population projections assumes:
- A base population at 30 June 2006 of 4.18 million. This is 58,000 or 1.4 percent higher than the 4.13 million projected from the 2004-base national population projections (series 5), mainly because observed net migration was higher than assumed. Net migration between 30 June 2001 and 2006 was an estimated 161,000, based on estimated population change less natural increase (births minus deaths), compared with the medium migration variant of 104,000 in the 2004-base projections.
- An average total fertility rate of 2.09 births per woman during 2007–11, dropping to 2.00 during 2012–16, 1.94 during 2017–21, 1.91 during 2022–26, and 1.90 thereafter. By comparison, the previous 2004-base projections assumed the average total fertility rate dropped from 1.95 during 2007–11 to 1.88 in 2012–16 and 1.85 thereafter. These higher fertility levels incorporate the recent rise in the total fertility rate, from about 1.9 in the year ended June 2002, to 2.0 in the year ended June 2006, and to 2.1 in the year ended June 2007.
- Net migration of 46,000 in the five years to 30 June 2011 and 50,000 in each subsequent five-year period. By comparison, the previous 2004-base projections assumed net migration of 38,000 in the five years to 30 June 2011, and 50,000 in each subsequent five-year period.
- Life expectancy at birth will increase to 82.5 years for males and 86.2 years for females in 2031. By comparison, the previous 2004-base projections assumed life expectancy at birth of 82.1 years for males and 85.9 years for females in 2031.
The combined effect of these changes is that the New Zealand population is expected to reach 4.39 million in 2011, 4.77 million in 2021, and 5.09 million in 2031 (series 5, 2006-base projections). By comparison, under series 5 of the 2004-base projections, the New Zealand population was expected to reach 4.29 million in 2011, 4.59 million in 2021, and 4.85 million in 2031.
Differences in the projected size and age-sex structure of the population contribute to differences between the previous and latest family and household projections in the number, size, and type of families and households. Series 5B of the latest national family and household projections indicates that the number of households will reach 1.66 million in 2011, 1.88 million in 2021, and 2.09 million in 2031. By comparison, series 5B of the previous national family and household projections (released 1 June 2005) indicated that the number of households would reach 1.65 million in 2011 and 1.84 million in 2021.
Which projection series should I use?
Three alternative series (designated low, medium, and high) have been produced for each area, using different combinations of fertility, mortality, migration, and living arrangement type assumptions. Users can make their own judgement as to which projection series is/are most suitable for their purposes. However, at the time of release, Statistics NZ considers the medium projection series the most suitable for assessing future family and household changes. This series is consistent with series 5B of the 2006-base National Family and Household Projections (released 8 December 2008) and the medium series of the 2006-base Subnational Population Projections (released 3 December 2007).
Households
Under the medium series, the number of households in New Zealand is projected to increase by 535,000 (an average of 1.2 percent a year), from 1.55 million in 2006 to 2.09 million in 2031. A household is defined as one person usually living alone, or two or more people usually living together and sharing facilities (eg eating facilities, cooking facilities, bathroom and toilet facilities, a living area), in a private dwelling.
All 16 regions are projected to have more households in 2031 than in 2006. The largest numerical increase is projected in the Auckland region, up an average of 1.8 percent a year from 466,000 in 2006 to 726,000 in 2031. This accounts for almost half (49 percent) of the national growth in the number of households projected over this period. By comparison, the Auckland region is projected to account for 62 percent of New Zealand's population growth between 2006 and 2031. By 2031, 35 percent of all households in New Zealand will be in the Auckland region, up from 30 percent in 2006.
The Bay of Plenty region, with a projected average increase of 1.3 percent a year, is the only other region projected to experience growth in the number of households that is above the national average.---PDF BREAK---
Among the 73 territorial authority areas in New Zealand, 63 are projected to have more households in 2031 than in 2006. Nine are projected to experience average annual growth of over 1.6 percent: Queenstown-Lakes district (2.3 percent); Manukau city and Selwyn district (2.1 percent); Rodney, Waimakariri, and Franklin districts (1.9 percent); Tauranga and Waitakere cities (1.8 percent); and Auckland city (1.7 percent). These areas are also projected to have the highest rates of population growth.
The greatest numerical growth in households over the 2006–31 period is projected to be in the four cities in the Auckland region – Auckland city (81,000), Manukau city (70,000), North Shore and Waitakere cities (both 36,000) – as well as in Christchurch city (40,000).
Household type
There are three broad household types that are projected: family households, one-person households, and other multi-person households.
In 2006, there were 1.12 million family households in New Zealand. Under the medium series, this number is projected to increase by 259,000 (an average of 0.8 percent a year), to reach 1.38 million in 2031. The number of households containing a family (or families) is projected to increase in 41 territorial authority areas and decline in the remaining 32 areas. Changes in the number of family households are closely related to changes in the number of families in each area (nationally there was an average of 1.04 families per family household in 2006).
The family household is by far the most common household type, accounting for 72 percent of all New Zealand households in 2006. However, its share of all households nationally is projected to decline to 66 percent by 2031. A decline in share is projected for all territorial authority areas.
The number of one-person households in New Zealand is projected to increase by 257,000 (an average of 2.2 percent per year) from 363,000 in 2006 to 619,000 in 2031. The relatively large increase in this type of household is mainly due to the increasing number of people at older ages, with 80 percent of the growth occurring among those aged 55 years and over. Of all people in one-person households, 67 percent are projected to be aged 55 years and over in 2031, compared with 59 percent in 2006. All territorial authority areas are projected to have more one-person households in 2031 than in 2006, with numbers in Rodney district, Waitakere city, Manukau city, Franklin district, Waikato district, Waimakariri district, Selwyn district, and Queenstown-Lakes district more than doubling over the 25-year period.
One-person households will account for a greater share of households in all territorial authority areas in 2031 compared with 2006. In 2031, the Buller (42 percent), Westland (41 percent), and Ruapehu (41 percent) districts are projected to have the highest shares of one-person households. These figures represent increases from 32, 29, and 28 percent, respectively, in 2006. The lowest shares of one-person households will be in Manukau city (19 percent), Selwyn district (23 percent), and North Shore and Porirua cities (both 25 percent). These shares are higher than the 2006 estimates for these areas of 14, 15, 19, and 18 percent, respectively.
Other multi-person households (households containing more than one person, but not containing a family) are projected to increase nationally from 68,000 in 2006 to 88,000 in 2031 – an increase of 20,000 or an average of 1.0 percent a year. Other multi-person households will account for 4 percent of all households throughout the projection period. People aged 18–29 years will continue to account for about half of all people in other multi-person households. The largest numerical increases in the number of other multi-person households between 2006 and 2031 are projected in Auckland city (4,400), Christchurch city (2,100), and Manukau city (2,000). Increases of between 200 and 1,500 are projected in another 13 territorial authority areas.
Average household size
Under the medium series, the average size of New Zealand households is projected to decrease from 2.6 people in 2006 to 2.4 people in 2031. Declining average household size is projected for all territorial authority areas, and reflects an increasing proportion of one-person households and a decrease in the average size of family households. Average family size is projected to decline largely because of an increase in the proportion of 'couple without children' families (which contain two people) and a decrease in the proportion of 'two-parent' families (which contain about four people, on average). These trends are driven mainly by the general ageing of the population. The population aged 50 years and over is projected to increase by 63 percent between 2006 and 2031, compared with 5 percent growth for the population aged under 50 years.
Differences in average household size between territorial authority areas reflect differences in family and household type, and to a lesser extent family size. In 2031, average household size is projected to be highest in Manukau city (3.0 people), Papakura district (2.7 people), and Porirua and Waitakere cities (both 2.6 people). These territorial authority areas also had the highest average household sizes in 2006, of 3.4, 2.9, 3.0, and 2.9 people, respectively. These areas have relatively low proportions of one-person households and relatively high proportions of family households with children.
In contrast, the smallest average household size in 2031 is projected to be 1.9 people in the Buller district. In 2006, the smallest average household size was 2.2 people in both the Buller and Thames-Coromandel districts. These areas have relatively high proportions of one-person households and relatively low proportions of family households with children.
Household change compared with population change
The projections indicate that household growth is likely in all regions and most territorial authority areas, including some areas projected to experience population decline. At the national level, the projected increase in the number of households (an average of 1.2 percent per year) between 2006 and 2031 is greater than the projected growth of both families (0.8 percent) and population (0.8 percent), reflecting the trend towards smaller average household size. The household growth rate is projected to exceed the population growth rate in all regions and territorial authority areas.
The medium series of the 2006-base subnational population projections indicates that three regions – Taranaki, West Coast, and Southland – are projected to have fewer people in 2031 than in 2006. However, all these regions are projected to experience an increase in the number of households. Similarly, 32 territorial authority areas are projected to have fewer people in 2031 than in 2006, but 22 of these are projected to have more households.
These trends are a further reflection of changes in the age structure of the population, with all territorial authority areas projected to have more older people (65 years and over) in 2031 than in 2006. In contrast, 53 territorial authority areas are projected to have fewer children (aged 0–14 years) in 2031.
Families
Under the medium series, the number of families in New Zealand is projected to increase by 269,000 (an average of 0.8 percent per year) between 2006 and 2031, from 1.17 million to 1.44 million. A family refers to a couple, with or without child(ren), or one parent with child(ren), usually living together in a household.
Thirteen of the 16 regions in New Zealand are projected to have more families in 2031 than in 2006. The largest increase in the number of families is projected in the Auckland region, with an annual average increase of 1.5 percent from 376,000 to 546,000. This accounts for 63 percent of the projected increase in the number of families at the national level. By 2031, 38 percent of all families in New Zealand are projected to live in the Auckland region, compared with 32 percent in 2006. The Bay of Plenty region (0.9 percent per year) is also projected to experience growth that exceeds the national average. Fewer families are projected in the Southland, West Coast, and Taranaki regions by 2031.
Among territorial authority areas, 40 are projected to have more families in 2031 than in 2006. Growth in the number of families is projected to slow at the national level over the projection period, and a similar pattern is likely for most subnational areas. This trend reflects the slowing of population growth and the changing age structure of the population. While 20 territorial authority areas are projected to record a decrease in the number of families between 2006 and 2016, 41 are projected to record a decrease between 2021 and 2031.
The four areas projected to experience the highest annual average percentage growth in the number of families between 2006 and 2031 are Queenstown-Lakes district (2.1 percent), Manukau city (1.9 percent), Selwyn district (1.7 percent), and Rodney district (1.5 percent).
These are also the areas projected to have the highest percentage growth in population and households. The largest numerical increases in families between 2006 and 2031 are projected in Manukau city (55,000), followed by Auckland city (49,000), Waitakere and North Shore cities (both 22,000), and Christchurch city (16,000).
Family type
There are three broad family types that are projected: 'couple without children' families, 'two-parent' families, and 'one-parent' families.
At the national level, the number of 'couple without children' families is projected to increase by an annual average of 1.8 percent, from 468,000 in 2006 to 730,000 in 2031. Couple without children families include (a) couples who will never have children, (b) couples who will have children in the future, and (c) couples whose children have left the parental home. Growth in (c) is expected to be the most significant, as the large number of people born after World War II reach 50 years and over. An increasing proportion of couples in (a) is also assumed to contribute to the increasing number of couple without children families, but to a lesser extent. Nearly all territorial authority areas are projected to have an average annual increase of at least 0.5 percent more couple without children families in 2031 than in 2006. The exceptions are South Waikato, Kawerau, Wairoa, Ruapehu, Rangitikei, Waimate, and Waitaki districts. The number of couple without children families is projected to more than double in Selwyn district (from 4,300 to 9,200), Queenstown-Lakes district (from 3,800 to 8,000), and Manukau city (from 26,000 to 54,000) over this period.
The number of 'two-parent' families in New Zealand is projected to decrease from 481,000 in 2006 to 425,000 by 2031. This is due to a decreasing likelihood of being in this living arrangement type at most ages, reflecting continued trends towards single parenting and fewer couples having children. However, 7 territorial authority areas are projected to have more two-parent families in 2031 than in 2006. These are areas projected to have significant population growth. Despite the increase in the number of two-parent families in these areas, the share of families in this family type is projected to decrease for all territorial authority areas – due to faster growth in the numbers of couple without children families and one-parent families.
Nationally, the number of 'one-parent' families is projected to increase by 63,000 (1.0 percent per year), from 219,000 in 2006 to 282,000 in 2031. Increases are projected for 45 territorial authority areas, with the highest in Manukau city (2.2 percent), Queenstown-Lakes district (2.1 percent), Selwyn district (2.0 percent), and Rodney district (1.8 percent). As children in families can be of any age, one-parent families include mature children living with an older parent.
By 2031, couple without children families are projected to be the most common family type in nearly all territorial authority areas. The exception is Manukau city, where two-parent families will remain the most common family type. In 2006, couple without children families were the most common family type for 50 territorial authority areas, while two-parent families were the most common family type for the remaining 23.
For technical information contact:
Rino Adair or Kim Dunstan
Christchurch 03 964 8700
Email: demography@stats.govt.nz
Next release ...
National Population Projections: 2009(base)–2061 will be released on 27 October 2009.