Index of each item in each line of the RPI calculation from Base

Summary

The requester asked for detailed RPI calculation data from January 2000 to May 2021, including line item indices, weights, and formula changes. The Cabinet Office disclosed data only from March 2008 onwards, stating that no records were held for the earlier period requested.

Key Facts

• The request covered RPI data from January 2000 to May 2021.
• The authority confirmed no records are held for data prior to March 2008.
• Monthly indices were supplied for the period March 2008 to May 2021.
• Weights were provided for two periods: March 2008 to January 2015, and February 2015 to present.
• Information created before October 11, 2011, was supplied under the Code of Practice rather than the Freedom of Information Act 2015.

Data Disclosed

• January 2000
• May 2021
• March 2008
• January 2015
• February 2015
• 11 October 2011
• 100
• 1881753
• 3 pages
• 1 document

Exemptions Cited

• Information created prior to 11 October 2011 is not subject to the Freedom of Information Act 2015
• No records held for data prior to March 2008

Original Request

Dear Sir/Madam, Item 1 Please could you provide the monthly index for every line item used in the RPI calculation from January 2000 to May 2021. It is necessary to request the indices this far back since that is when they were last rebased at 100. To be clear, when I ask for every line item, I would like every underlying monthly line item index for every category making up the RPI, as well as the monthly index for the category itself. Item 2 Weights for the underlying monthly line items. Item 3 Any dates at which the indices were unlinked or chain linked, for reweighting or otherwise. For example, when RPI moved from the Carli formula to the Jevons formula. Item 4 Any other information which would be required to recalculate the monthly RPI from January 2000 to present. I appreciate that this is a lot of information to request, however, I do think it's justified because: - IOM RPI is still of importance to many commercial transactions - It will be of great use to me, and to the Manx public in general, and so will be much appreciated - I expect the information is readily available and so not difficult to reproduce - This information request is still much less information than the UK publish about their inflation indices I look forward to receiving this information.

Data Tables (4)

Full Response Text

Government Office Douglas Isle of Man IM1 3PN Telephone: (+44) 01624 686244 Website: www.gov.im/co

Our ref: 1881753 14 July 2021

Dear ###

We write further to your request which was received on 30 June 2021 and which states:

"Dear Sir/Madam, Item 1 Please could you provide the monthly index for every line item used in the RPI calculation from January 2000 to May 2021. It is necessary to request the indices this far back since that is when they were last rebased at 100. To be clear, when I ask for every line item, I would like every underlying monthly line item index for every category making up the RPI, as well as the monthly index for the category itself. Item 2 Weights for the underlying monthly line items. Item 3 Any dates at which the indices were unlinked or chain linked, for reweighting or otherwise. For example, when RPI moved from the Carli formula to the Jevons formula. Item 4 Any other information which would be required to recalculate the monthly RPI from January 2000 to present. I appreciate that this is a lot of information to request, however, I do think it's justified because: - IOM RPI is still of importance to many commercial transactions - It will be of great use to me, and to the Manx public in general, and so will be much appreciated - I expect the information is readily available and so not difficult to reproduce - This information request is still much less information than the UK publish about their inflation indices

I look forward to receiving this information." A Freedom of Information request can only be made in respect of information created on or before 11 October 2011. As part of your request is for information created prior to this date we are not obliged to respond to it as a freedom of information request. The information held prior to October 2011 has been supplied under the Code of Practice on Access to Government Information which can be found here: www.gov.im/media/1358113/foia-code-of-practice.pdf. Item 1 Please could you provide the monthly index for every line item used in the RPI calculation from January 2000 to May 2021. Monthly index items from March 2008 through to May 2021 is supplied, see attached spreadsheet. Please note no records are held in relation to data prior to March 2008. Item 2 Weights for the underlying monthly line items. Information has also been included on the weights of the items in effect at March 2008 through to January 2015, and from February 2015 through to current. Item 3 Any dates at which the indices were unlinked or chain linked, for reweighting or otherwise. For example, when RPI moved from the Carli formula to the Jevons formula. Where the indices have been chain linked, this has been made clear above the relevant month, similarly where the formula was changed. Item 4 Any other information which would be required to recalculate the monthly RPI from January 2000 to present. The RPI index back to 2000 has also been provided for ease of reference.

Please quote the reference number 1881753 in any future communications.

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dissatisfied with this response, and should be made as soon as practicable. We will respond as soon as the review has been concluded. If you are not satisfied with the result of the review, you then have the right to appeal to the Information Commissioner for a decision on; 1. Whether we have responded to your request for information in accordance with Part 2 of the Freedom of Information Act 2015; or 2. Whether we are justified in refusing to give you the information requested.
In response to an application for review, the Information Commissioner may, at any time, attempt to resolve a matter by negotiation, conciliation, mediation or another form of alternative dispute resolution and will have regard to any outcome of this in making any subsequent decision. More detailed information on your right to a review can be found on the Information Commissioner’s website at www.inforights.im. Should you have any queries concerning this letter, please do not hesitate to contact me. Further information about freedom of information requests can be found at www.gov.im/foi. I will now close your request as of this date.

Yours sincerely