FOI Reference: FOI/2021/3097
You asked
Under the Freedom of Information Act of 2000, I am writing to request that the ONS makes publicly available in electronic format the updates to all MIPs parameters described in Section 11.5.1 and in Table 11 of the 2019 technical manual.
I wanted to request that the ONS provides all the updates to these parameters (including the date of update) since the publication of the 2019 technical manual which was last revised on 18 September 2019.
For your convenience, I have listed the relevant MIPs parameters by source below, including their values published in the 2019 technical manual. These values will have changed since the last publication of the technical manual, and I am requesting that the ONS makes publicly available all such updates and changes to parameters, including (1) the updated values, (2) the date of update, and (3) edition/year of the relevant sources used. If some parameters were updated multiple times since 2019, I would like to request the same information for all consecutive updates.
General Household Survey
1. Proportion of purchase price that is borrowed - 55%
Council of Mortgage Lenders' survey of mortgage lending
2. The shares of repayment and endowment mortgages - 75% and 25%, respectively
Living Cost and Food Survey
3. Average initial length mortgage - 23 years, equivalent to 276 calendar months
4. Proportion of index household holding mortgages of each vintage - column e in Table 11
5. Proportion of all index households who are owner occupiers - 72%
6. Proportion of all index households who have been at the same address for less than 23 years - 76%
7. Proportion with mortgages - 73%
HM Land Registry
8. House price index (HPI) - could you please advise whether the house price index used to adjust the average house price within the MIPs calculation as part of each monthly RPI release is the same index used to calculate the depreciation series (ie, the unrevised arithmetic average HPI index)?
We said
Thank you for your request.
The information you have requested in Questions 1 to 7 would need to be commissioned independently, as this information is not routinely produced by our teams. Such bespoke services are subject to legal frameworks, disclosure controls, resources and agreement of costs. If you would like to request this bespoke analysis, please contact cpi@ons.gov.uk to discuss your enquiry further. Please note, there will be a charge for this work which would be subject to our charging policy. As this information is reasonably accessible via our bespoke services route, Section 21 of the Freedom of Information Act 2000 (FOIA) applies.
With regards to Question 8 of your query, we can confirm that the two series referenced are different.