Appendices
A Data
A.1 Household Savings Survey
The 2001 Household Savings Survey covered those over 18 years of age living in private dwellings and usually resident in New Zealand. People living in non-private dwellings such as institutions, motels, rest homes or hostels were excluded, so were those on offshore islands (except Waiheke Island).
For the core sample 6,600 households were approached. One person from those qualifying in the household was chosen at random, and information was collected from and about that individual. If they had a partner, information was collected for the couple, i.e., where the respondent and their partner were living in the same household the couple was interviewed as a single unit. In order to improve the accuracy of estimates for Māori, a booster sample was used. The response rate was 74% and the final sample includes 5,374 households (2,392 non-partnered individuals and 2,982 couples). In total, a population of 930,900 non-partnered individuals and 1,711,800 individuals in couples, or a total of 2,642,700 people, are covered.[18] The survey results, when appropriately weighted, represent about 98% of the resident adult population.
A.2 Differences between HSS and SOFIE data
| HSS | SOFIE | |
|---|---|---|
| Statistical unit | The non-partnered individual or the couple | The individual and the household. SOFIE provides no information on whom a person is partnered with, but we can infer this from people's role in their family nucleus and form partnered individuals into couples accordingly. The couple's income or wealth is made up of the income/wealth of both partners while the age of the couple refers to the age of the older partner. |
| Property | Non-partnered individuals/couples were asked for the dollar value of their share in a property. | Individuals were asked for the total value of each property and the number of other people who also own that property. We assume equal ownership shares among owners. |
| Mortgages | Mortgages were collected for each property. | There is only one figure which refers to the total value of all mortgages, but no information on the number of mortgages or which property the mortgages are for. We assume that the total mortgage value is split between owner-occupied and other residential property such that the gearing ratio is equal between the two classes of property. [19] |
| Household items | No data | We ignore household items in the calculation of wealth, as these assets depreciate over time and they can not easily be liquidated. These assets are also valued inconsistently across individuals.[20] |
| Pension schemes | Values were provided by the Government Actuary and are consistent with the Reserve Bank's aggregate data. | Due to errors in the questionnaire, there is evidence that the participation rates in pension schemes and reported values of schemes are markedly lower than indicated by other sources.[21] The errors are complex and we have been unable to remedy them. We take the data as is, acknowledging that these errors understate net worth by 2% on average and thus render our results ‘conservative.' |
Notes
- [18]Although the survey is entitled a ‘household’ survey, it does not pertain strictly to households per se. Rather, it covers non-partnered individuals and couples.
- [19]We acknowledge that investment properties are normally more highly geared (for tax benefits), so such division of mortgages would tend to overstate borrowing for owner-occupied properties.
- [20]The methods that were used to evaluate household items include: 1) Insured value for replacement (59.4%); 2) Insured value not for replacement (6.3%); 3) Amount that would be received if sold (13%); 4) Amount that was paid (8.1%); 5) Other method of estimation (11.7%); 6) Don’t know; 7) Refused; and 8) Missing.
- [21]Informal communications and unpublished notes from staff of Statistics New Zealand.
