Share of wealth held by the top ten percent of wealthiest people in New Zealand

Net worth: is the value of a person or household’s assets, minus their liabilities.
Assets: are something a person or household owns, such as property or investments.
Liability: is an obligation such as a debt, mortgage, or loan. The liability's holder is obliged, under specific circumstances, to provide a payment or series of payments to whomever they are liable to.
Household: is either one person who usually resides alone, or two or more people who usually reside together and share facilities (eg for eating or cooking) in a private dwelling. A household may contain one or more families, other people in addition to a family, or no families at all, such as unrelated people living together. Statistics New Zealand don't include non-private dwellings such as hostels, or the rest home and hospital sections of retirement homes (serviced apartments within retirement homes are counted as private dwellings).

Age standardisation: To mitigate the effects of the Māori and Pacific population having a much younger age structure than the total New Zealand population, age standardisation technique was applied. Without age standardisation, median and mean figures for the variable of interest (eg net worth) by age-group, can potentially be distorted. Age standardisation is a commonly applied technique to control such distortions; it allows more meaningful comparisons between the sub-populations.

https://datainfoplus.stats.govt.nz/item/nz.govt.stats/ba211f92-b4ad-4b3c-9630-662138009889?_ga=2.167775521.1044871764.1671032349-526904916.1660871371

The following caveats were reported by Stats NZ:
- There are occasions where respondents mentioned they have other property, but it is scoped out of the HES part of the questionnaire because it is for business purposes. Sometimes the respondent then did not mention it in the property, business, or trust sections (where we expected they would). This may have resulted in under-reporting of the value of property assets.
- Some respondents said they received superannuation contributions from their employer but did not then give details of a superannuation scheme. This may have lead to under-reporting of superannuation schemes.
- Some respondents did not report all the businesses they owned. Some partners living together in a household responded that they both owned all of a business. Where this was identified and could be verified it was corrected.
- In regards to family trusts, some respondents were unsure of their relationship to the trust, which may have led to fewer respondents identifying as a settlor or quasi settlor. This may have caused an under-reporting of trust wealth.
- To reduce respondent burden, respondents were not asked to provide the value of smaller-value items (eg valuables under $5000). This may have resulted in some under-reporting.

In 2014/15 many respondents did not see bank accounts as investments. As a result, the number and value of assets held in bank accounts were undervalued. To improve this, in 2017/18 bank accounts were asked about separately from other investments and details of many more bank accounts were collected. However, quite a few bank accounts with low values were still collected. The same approach was used in 2020/21.

At URL provided, under the Download data section select 'Household net worth statistics: Year ended June 2021' Excel file.
Sheets 7.01, 7.02, 7.03, 7.04, 8.03, and 8.04 were reformatted by Figure.NZ for processing purposes.

Household net worth statistics aims to provide a picture of the net worth (wealth) of New Zealanders, by looking at their household assets and liabilities – financial and non-financial.

The Net Worth Household Statistics were collected as a component of the Household Economic Survey. The sample size was approximately 5,500 households, due to COVID-19 disruptions. The latest survey was carried out from 08 August 2020 to 30 June 2021.
The survey is a sample survey that uses statistical weights to calculate income and expenditure estimates for the total New Zealand population. For Household Economic Survey the weights used were based on the Census 2018 population.
The target population for HES is the usually resident population of New Zealand living in private dwellings, aged 15 years and over.