Treasury Analytical Note : Trends in the household income distribution: 2007-2021
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Summary
These detailed outputs accompany the Treasury Analytical Note “Trends in the household income distribution: 2007-2021” https://www.treasury.govt.nz/publications/an/an-23-01
This note lays the groundwork for future research by presenting comprehensive data on household income distributions over the past 14 years. It goes beyond headline statistics on incomes, inequality, and poverty by using unit record data from Stats NZ to supplement existing outputs and reports, such as Perry (2019, 2022). Through visual representations, this note presents household income distributions for various types of households from 2007 to 2021, shedding light on trends and patterns. Additionally, the note delves into the impact of an aging population by creating a counterfactual distribution based on 2007 age demographics, allowing for further investigation into this important demographic shift. The detailed data and analyses presented in this note serve as a valuable foundation for future work in understanding household incomes in New Zealand.
Data description
The unit record data used in this analysis were provided by Stats NZ and cover the period from 2007 to 2021. This is the same dataset that is used by Stats NZ to create child poverty and household income statistics.
For 2019–2021, the data are derived from the Household Economic Survey (HES) linked to administrative income data in the Integrated Data Infrastructure (IDI). Stats NZ increased the size of HES to around 20,000 households in 2019 as part of their work to improve Child Poverty measurement (Stats NZ, 2022).
For years prior to 2019, this analysis uses data that was derived by Stats NZ to produce a baseline for the Child Poverty reporting regime. In these years, the HES was a much smaller survey of around 3,500–5,000 households. For before housing cost incomes, the data comprise HES combined with the Household Labour Force Survey (HLFS) linked to administrative data in the IDI. After housing cost incomes are only derived from HES combined with administrative data because HLFS does not contain information on housing costs.
This means that there is a series break in 2019, due to different data sources and sample sizes. However, the data show consistent trends in the distributions and statistics of interest to this paper over this time period.
IDI Disclaimer
These results are not official statistics. They have been created for research purposes from the Integrated Data Infrastructure (IDI) which is carefully managed by Stats NZ. For more information about the IDI please visit https://www.stats.govt.nz/integrated-data/. The results are based in part on tax data supplied by Inland Revenue to Stats NZ under the Tax Administration Act 1994 for statistical purposes. Any discussion of data limitations or weaknesses is in the context of using the IDI for statistical purposes, and is not related to the data’s ability to support Inland Revenue’s core operational requirements.
Results
Equivalised income
Household Equivalised Income Distributions
Distributions between 2007 and 2021
Distributions in 2007, 2014, and 2021
Changes over seven years
Unit of analysis - person vs household
Household Equivalised Income - Summary Statistics
Deciles
Inequality
Average changes in deciles
| Proportion | Dollar | Proportion | Dollar | ||
|---|---|---|---|---|---|
| All | Decile 1 | 3.38% | $355 | 2.52% | $473 |
| Decile 2 | 2.66% | $443 | 2.38% | $560 | |
| Decile 3 | 2.39% | $499 | 2.29% | $656 | |
| Decile 4 | 2.31% | $590 | 2.28% | $776 | |
| Decile 5 | 2.29% | $696 | 2.15% | $846 | |
| Decile 6 | 2.14% | $761 | 1.96% | $894 | |
| Decile 7 | 1.96% | $829 | 1.85% | $978 | |
| Decile 8 | 1.69% | $877 | 1.84% | $1,144 | |
| Decile 9 | 1.85% | $1,249 | 1.73% | $1,356 |
Household types
Distributions of each household type in 2007, 2014, 2021
Number of people by household type and income
Trends in BHC income between 2007 and 2021
Trends in AHC income between 2007 and 2021
Seven year change in BHC income between 2014 and 2021
Seven year change in AHC income between 2014 and 2021
Medians
Inequality
Small sample sizes for some groups result in noisy data. Use the zoom feature to focus in on the group you are interested in.
Average change in deciles
| Proportion | Dollar | Proportion | Dollar | ||
|---|---|---|---|---|---|
| Multi-adult | Decile 1 | 1.95% | $230 | 1.96% | $439 |
| Decile 2 | 1.20% | $272 | 1.50% | $488 | |
| Decile 3 | 0.97% | $299 | 1.53% | $610 | |
| Decile 4 | 0.94% | $349 | 1.39% | $649 | |
| Decile 5 | 0.94% | $405 | 1.34% | $713 | |
| Decile 6 | 0.85% | $423 | 1.27% | $765 | |
| Decile 7 | 1.13% | $630 | 1.06% | $716 | |
| Decile 8 | 1.11% | $723 | 1.15% | $886 | |
| Decile 9 | 1.59% | $1,272 | 1.34% | $1,276 | |
| Multi-adult with children | Decile 1 | 3.73% | $409 | 2.45% | $459 |
| Decile 2 | 2.79% | $482 | 2.52% | $629 | |
| Decile 3 | 2.54% | $548 | 2.33% | $692 | |
| Decile 4 | 2.44% | $620 | 2.28% | $774 | |
| Decile 5 | 2.62% | $758 | 2.25% | $865 | |
| Decile 6 | 2.42% | $802 | 2.13% | $914 | |
| Decile 7 | 2.39% | $902 | 2.06% | $1,001 | |
| Decile 8 | 2.38% | $1,072 | 2.20% | $1,241 | |
| Decile 9 | 2.60% | $1,531 | 2.40% | $1,689 | |
| Multi-adult, 65+ | Decile 1 | 4.92% | $677 | 2.96% | $590 |
| Decile 2 | 2.08% | $402 | 2.40% | $539 | |
| Decile 3 | 2.45% | $530 | 2.87% | $711 | |
| Decile 4 | 2.92% | $724 | 3.28% | $950 | |
| Decile 5 | 3.01% | $893 | 3.47% | $1,165 | |
| Decile 6 | 2.78% | $986 | 3.20% | $1,250 | |
| Decile 7 | 2.59% | $1,096 | 2.99% | $1,396 | |
| Decile 8 | 2.02% | $1,067 | 2.90% | $1,616 | |
| Decile 9 | 1.51% | $1,085 | 2.64% | $1,869 | |
| Single | Decile 1 | NA | $231 | 5.29% | $572 |
| Decile 2 | 3.97% | $349 | 1.75% | $325 | |
| Decile 3 | 1.58% | $218 | 1.23% | $297 | |
| Decile 4 | 1.78% | $321 | 1.24% | $395 | |
| Decile 5 | 2.37% | $549 | 1.36% | $532 | |
| Decile 6 | 1.63% | $483 | 1.02% | $471 | |
| Decile 7 | 1.61% | $592 | 1.01% | $535 | |
| Decile 8 | 1.41% | $646 | 1.17% | $723 | |
| Decile 9 | 2.03% | $1,194 | 1.17% | $931 | |
| Single with children | Decile 1 | NA | $4 | 1.13% | $160 |
| Decile 2 | 1.73% | $188 | 1.62% | $301 | |
| Decile 3 | 1.99% | $252 | 1.83% | $386 | |
| Decile 4 | 1.90% | $271 | 2.11% | $486 | |
| Decile 5 | 2.15% | $339 | 2.04% | $516 | |
| Decile 6 | 1.81% | $334 | 2.01% | $563 | |
| Decile 7 | 2.34% | $479 | 2.09% | $647 | |
| Decile 8 | 1.73% | $428 | 2.14% | $754 | |
| Decile 9 | 0.92% | $298 | 1.37% | $601 | |
| Single, 65+ | Decile 1 | 4.70% | $485 | 2.25% | $449 |
| Decile 2 | 1.94% | $299 | 1.96% | $408 | |
| Decile 3 | 1.56% | $270 | 2.12% | $451 | |
| Decile 4 | 1.70% | $311 | 2.33% | $507 | |
| Decile 5 | 1.87% | $359 | 2.49% | $560 | |
| Decile 6 | 1.92% | $399 | 2.59% | $630 | |
| Decile 7 | 2.07% | $498 | 2.82% | $788 | |
| Decile 8 | 1.71% | $560 | 3.15% | $1,119 | |
| Decile 9 | 1.23% | $562 | 2.82% | $1,428 |
Composition of population over time
By Household type
By age of the oldest
By age of the youngest
By birth year of the oldest in household
By age of youngest child and household type
By beneficiary status
Counterfactual - 2007 age compositions
These figures compare the distributions to counterfactuals that are based on the 2007 “Age of oldest” compositions. This isolates the impact of the changing age distribution from other changes.
Comparing BHC distributions based on age of oldest in the household
BHC distribution - Difference to counterfactual based on age of oldest in the household
Comparing full BHC distribution to counterfactual
Comparing AHC distributions based on age of oldest in the household
AHC distribution - Difference to counterfactual based on age of oldest in the household
Comparing full AHC distribution to counterfactual
Beneficiary status
Working age households without children
Distributions in 2007, 2014, 2021
Number of people by household type and income
Trends in BHC income between 2007 and 2021
BHC income 2007, 2014, and 2021
Trends in AHC income between 2007 and 2021
AHC income 2007, 2014, and 2021
Seven year change in BHC income between 2014 and 2021
Seven year change in AHC income between 2014 and 2021
Medians
Inequality
Small sample sizes for some groups result in noisy data. Use the zoom feature to focus in on the group you are interested in.
Average change in deciles
| Proportion | Dollar | Proportion | Dollar | ||
|---|---|---|---|---|---|
| Beneficiary : Multi-adult | Decile 1 | 5.08% | $385 | 1.37% | $263 |
| Decile 2 | 2.73% | $409 | 1.83% | $452 | |
| Decile 3 | 3.08% | $602 | 1.93% | $568 | |
| Decile 4 | 1.96% | $493 | 2.18% | $746 | |
| Decile 5 | 1.93% | $578 | 1.87% | $718 | |
| Decile 6 | 1.61% | $557 | 1.73% | $759 | |
| Decile 7 | 0.67% | $288 | 1.91% | $947 | |
| Decile 8 | 0.78% | $391 | 2.16% | $1,213 | |
| Decile 9 | 1.46% | $851 | 1.57% | $1,057 | |
| Beneficiary : Multi-adult, 65+ | Decile 1 | 3.54% | $466 | 3.21% | $636 |
| Decile 2 | 4.28% | $740 | 2.21% | $509 | |
| Decile 3 | 4.28% | $844 | 2.18% | $567 | |
| Decile 4 | 3.23% | $760 | 3.08% | $898 | |
| Decile 5 | 2.93% | $814 | 3.03% | $1,004 | |
| Decile 6 | 3.57% | $1,093 | 3.02% | $1,080 | |
| Decile 7 | 4.14% | $1,360 | 3.32% | $1,322 | |
| Decile 8 | 3.81% | $1,449 | 3.16% | $1,402 | |
| Decile 9 | 2.37% | $1,162 | 2.22% | $1,268 | |
| Beneficiary : Single | Decile 1 | NA | -$66 | 1.35% | $187 |
| Decile 2 | 0.14% | $13 | 1.14% | $186 | |
| Decile 3 | -0.05% | -$6 | 1.12% | $197 | |
| Decile 4 | -0.16% | -$20 | 1.21% | $233 | |
| Decile 5 | 0.47% | $63 | 1.04% | $218 | |
| Decile 6 | 0.04% | $6 | 1.02% | $241 | |
| Decile 7 | 0.72% | $121 | 0.89% | $235 | |
| Decile 8 | 0.49% | $96 | 0.71% | $219 | |
| Decile 9 | 2.21% | $511 | 0.98% | $383 | |
| Beneficiary : Single, 65+ | Decile 5 | NA | NA | NA | NA |
| Non beneficiary : Multi-adult | Decile 1 | 1.27% | $172 | 1.82% | $456 |
| Decile 2 | 1.27% | $347 | 1.61% | $597 | |
| Decile 3 | 0.95% | $333 | 1.58% | $713 | |
| Decile 4 | 1.31% | $530 | 1.48% | $765 | |
| Decile 5 | 1.20% | $556 | 1.32% | $773 | |
| Decile 6 | 1.06% | $565 | 1.23% | $797 | |
| Decile 7 | 1.22% | $726 | 1.16% | $841 | |
| Decile 8 | 1.35% | $933 | 1.39% | $1,140 | |
| Decile 9 | 1.69% | $1,433 | 1.48% | $1,484 | |
| Non beneficiary : Multi-adult, 65+ | Decile 1 | 5.06% | $704 | 2.85% | $571 |
| Decile 2 | 1.91% | $371 | 2.36% | $526 | |
| Decile 3 | 2.32% | $502 | 2.92% | $719 | |
| Decile 4 | 2.94% | $733 | 3.39% | $974 | |
| Decile 5 | 2.84% | $867 | 3.55% | $1,197 | |
| Decile 6 | 2.44% | $912 | 3.25% | $1,301 | |
| Decile 7 | 2.43% | $1,092 | 3.21% | $1,549 | |
| Decile 8 | 2.30% | $1,265 | 3.03% | $1,744 | |
| Decile 9 | 1.76% | $1,284 | 2.90% | $2,122 | |
| Non beneficiary : Single | Decile 1 | NA | $0 | 14.36% | $1,047 |
| Decile 2 | 10.39% | $930 | 2.90% | $763 | |
| Decile 3 | 3.74% | $716 | 2.20% | $776 | |
| Decile 4 | 2.33% | $603 | 1.63% | $671 | |
| Decile 5 | 2.11% | $648 | 1.21% | $574 | |
| Decile 6 | 1.89% | $681 | 1.21% | $640 | |
| Decile 7 | 1.65% | $705 | 1.41% | $837 | |
| Decile 8 | 1.67% | $880 | 1.46% | $1,001 | |
| Decile 9 | 2.25% | $1,483 | 1.50% | $1,295 | |
| Non beneficiary : Single, 65+ | Decile 1 | 4.32% | $462 | 2.18% | $440 |
| Decile 2 | 1.88% | $294 | 1.96% | $409 | |
| Decile 3 | 1.48% | $260 | 2.11% | $450 | |
| Decile 4 | 1.70% | $313 | 2.34% | $509 | |
| Decile 5 | 1.89% | $363 | 2.49% | $561 | |
| Decile 6 | 1.88% | $393 | 2.55% | $621 | |
| Decile 7 | 2.17% | $524 | 2.84% | $796 | |
| Decile 8 | 1.58% | $522 | 3.17% | $1,129 | |
| Decile 9 | 1.27% | $582 | 2.85% | $1,447 |
Working age households with children
Distributions in 2007, 2014, 2021
Number of people by household type and income
Trends in BHC income between 2007 and 2021
BHC income 2007, 2014, and 2021
Trends in BHC income between 2007 and 2021
AHC income 2007, 2014, and 2021
Seven year change in BHC income between 2014 and 2021
Seven year change in AHC income between 2014 and 2021
Medians
Inequality
Small sample sizes for some groups result in noisy data. Use the zoom feature to focus in on the group you are interested in.
Average change in deciles
| Proportion | Dollar | Proportion | Dollar | ||
|---|---|---|---|---|---|
| Beneficiary : Multi-adult with children | Decile 1 | 2.44% | $234 | 2.08% | $342 |
| Decile 2 | 1.80% | $271 | 1.94% | $404 | |
| Decile 3 | 2.02% | $376 | 2.33% | $560 | |
| Decile 4 | 1.42% | $314 | 1.89% | $521 | |
| Decile 5 | 1.47% | $375 | 1.93% | $591 | |
| Decile 6 | 2.00% | $561 | 1.89% | $642 | |
| Decile 7 | 1.99% | $618 | 1.82% | $688 | |
| Decile 8 | 2.25% | $780 | 1.67% | $724 | |
| Decile 9 | 2.02% | $862 | 1.72% | $883 | |
| Beneficiary : Single with children | Decile 1 | 0.44% | $38 | 1.41% | $224 |
| Decile 2 | 1.60% | $173 | 1.32% | $244 | |
| Decile 3 | 1.93% | $234 | 1.53% | $309 | |
| Decile 4 | 1.65% | $223 | 1.61% | $348 | |
| Decile 5 | 1.84% | $262 | 1.75% | $403 | |
| Decile 6 | 1.92% | $291 | 1.78% | $441 | |
| Decile 7 | 1.45% | $251 | 1.50% | $397 | |
| Decile 8 | 1.78% | $343 | 1.69% | $487 | |
| Decile 9 | 1.70% | $412 | 1.86% | $600 | |
| Non beneficiary : Multi-adult with children | Decile 1 | 3.43% | $406 | 2.63% | $540 |
| Decile 2 | 2.68% | $494 | 2.46% | $667 | |
| Decile 3 | 2.77% | $628 | 2.39% | $766 | |
| Decile 4 | 2.80% | $740 | 2.24% | $823 | |
| Decile 5 | 2.70% | $827 | 2.16% | $889 | |
| Decile 6 | 2.45% | $860 | 2.05% | $943 | |
| Decile 7 | 2.49% | $996 | 1.98% | $1,027 | |
| Decile 8 | 2.36% | $1,145 | 2.28% | $1,383 | |
| Decile 9 | 2.85% | $1,783 | 2.43% | $1,807 | |
| Non beneficiary : Single with children | Decile 1 | NA | -$278 | 2.81% | $187 |
| Decile 2 | NA | $245 | 3.94% | $721 | |
| Decile 3 | 1.63% | $266 | 2.32% | $585 | |
| Decile 4 | 1.66% | $319 | 2.02% | $591 | |
| Decile 5 | 1.43% | $309 | 1.80% | $590 | |
| Decile 6 | 0.63% | $158 | 1.88% | $670 | |
| Decile 7 | -0.15% | -$44 | 1.40% | $555 | |
| Decile 8 | -0.27% | -$95 | 0.96% | $433 | |
| Decile 9 | 0.47% | $198 | 0.81% | $438 |