Statistisches Bundesamt
Consumer price index of Germany
General information
February 2013
Periodicity: irregular
Published in 20.02.2013
For further information about this puplication please contact:
Phone: +49 (0) 611 / 75 47 77; Fax: +49 (0) 611 / 75 36 22;
www.destatis.de/contact
© Statistisches Bundesamt, Wiesbaden 2012
Reproduction and distribution, also of parts, are permitted provided that the source is mentioned.
Introduction
The consumer price index for Germany (CPI) measures the average price changes of all goods and services
purchased by households for consumption purposes. Up to 2002, the index was known and published as the
"consumer price index for all private households in Germany". The renaming, however, did not involve any
content-related modifications.
In addition, the
– index of retail prices and the
– harmonised index of consumer prices
are compiled for Germany.
Consumer price indices for specific types of households for both the "former territory of the Federal Republic"
and the "new Länder and Berlin-East" (discontinued indices) are not computed anymore.
At regular intervals (usually every five years), the consumer price index is revised, which means that the index
computation is based on more recent patterns of household consumption. At the same time, the survey
catalogue is revised systematically and some methodological changes are carried out. The indices are
recalculated from January of the new base year, with the new index figures replacing the previously published
results for that period. Results dating back even further are not recalculated but only formally rebased using
the new base year.
In the reference month January 2013, 2010 was adopted as the new price base year, replacing the previous
base year 2005. The new weighting pattern will remain unchanged until the next scheduled revision.
Measuring index changes
From the point of view of consumers, changes in the index from one point in time to another (calculated as
percentage changes) can be interpreted as the general rate of price change.
The index development in terms of percent can be computed by the following formula:
((new index position / previous index position) • 100) – 100
Calculation of amounts of money
If the index development requires that a new amount of money be calculated, the following formula is to be
used:
(former amount • new index position) / previous index position = new amount
Measuring changes in the purchasing power
Changes in the purchasing power of the money consumers have at their disposal can also be calculated by
means of the consumer price index. The following formula is to be used:
((previous index position / new index position) • 100) – 100
The results of all these calculations are independent of the base year selected, except for some minor
differences due to rounding.
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Using indices in stable-value clauses
Consumer price indices and indices of retail prices are often used as reference values in stable-value clauses
of tenancy, lease, delivery, pension and other agreements on continuous payments. Users of stable-value
clauses laid down in contracts which are based on discontinued indices will need to recalculate the stablevalue clauses on the basis of the consumer price index for Germany. The Federal Statistical Office offers a
range of services to help you with these calculations, some of which require a lot of work.
You will find an interactive program on the internet at www.destatis.de/wsk/, which provides mathematical
support to help you with the adjustment of stable-value clauses. Apart from the changeover from discontinued
indices to the consumer price index for Germany, the program will enable you to compute rates of change for
calendar months and calendar years (starting and ending dates flexible).
In addition, detailed German-language instructions are available for download from www.destatis.de „ Zahlen
& Fakten „ Preise „ Verbraucherpreisindizes „ Wertsicherungsklauseln (Anleitung für die Berechnung …) or
can be ordered by calling +49 (0) 611 / 75 47 77.
As an additional service at a charge of EUR 30.-, we offer to carry out the changeover calculations for you. In
that case, you will be required to complete a German-language form, which you can obtain:
– on the internet at
www.destatis.de „ Zahlen & Fakten „ Preise „ Verbraucherpreisindizes „ Wertsicherungsklauseln
(Formblatt)
– by using our faxback service: +49 (0) 611 / 75 36 22
– by calling +49 (0) 611 / 75 47 77
We would like to point out, however, that there will be no difference between calculations carried out by us and
calculations you make online.
The German-language leaflet on point-based stable-value clauses versus percentage-based stable-value
clauses offers information for contracting parties using such clauses. It too can be found on the internet at the
address cited above (Merkblatt). Alternatively, it can be ordered by calling +49 (0) 611 / 75 47 77.
A separate leaflet containing instructions on the use of retail prices indices in stable-value clauses can also be
ordered by calling either of the two telephone numbers listed above.
Information on the relevant legal provisions
The German law on extrajudical services of justice (Rechtsdienstleistungsgesetz, RDG) does not authorise the Federal
Statistical Office (Destatis) to provide any legal counselling or any services beyond mere mathematical support. As regards
queries about consumer price indices and their application in stable-value clauses, Destatis must restrict itself to providing
general technical and methodological advice.
If you need specific advice please contact your lawyer or notary public or a consumer agency.
In this context, we would like to draw your attention to the expert opinion on "Änderung des Verbraucherpreisindex;
Auswirkungen auf Wertsicherungsklauseln" (Changes in the consumer price index: impact on stable-value clauses) of the
German Notarial Institute (DNotI), which was published in the DNotI Report No. 2/2003. You will find the report on the
following web-page: http://www.dnoti.de/Report/2003/rep0203.htm
The legal provisions concerning stable-value clauses are laid down in the Price Clause Act (PrKG) of 7 September 2007 (Federal
Law Gazette I, pp. 2246, 2247) and in Article 557b of the Civil Code (BGB) concerning "index-linked rents". With the
introduction of the new Price Clause Act, the former procedure for authorisation by the Bundesamt für Wirtschaft und
Ausfuhrkontrolle (Federal Office of Economics and Export Control) is no longer required.
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Tips concerning the agreement of new stable-value clauses
•
We recommend you to base new stable-value clauses on the consumer price index for Germany and to
convert existing clauses with a long remaining life in accordance with this index.
How appropriate is the harmonised index of consumer prices (HICP)?
Since the mid-1990s, a harmonised index of consumer prices (HICP) has been calculated for Germany. The HICP was
developed with the aim of making price change rates comparable at international level and of merging them to form
an overall inflation rate for the European area and the European Monetary Union. This price index will be further
developed in the coming years. The primary objective behind producing this index is to measure inflation. Hence,
applying this index as a compensatory measure to contracts with stable-value clauses is not impossible but rather
complicated.
•
To reduce the problems involved with the changeover to a new base year, it is also advisable to
express changes in percent – not in points. In such cases the price base year is of no importance.
•
Consumer price indices are calculated for calendar months and years, but not for reference dates. A
wording like "the index effective on 1 January 2000" often leads to interpretation-related legal
disputes and should be avoided by all means.
All the information provided here describes adequate procedures from a statistical point of view.
How to deal with old stable-value clauses that are based on points
The services we offer concerning stable-value clauses are deliberately designed to provide support for the
calculation of point-based clauses only if they do not go beyond December 2002 as the starting point of the
calculation. As far as later adjustments are concerned, we recommend you to compute changes only in terms
of percent. Contracting parties will be independent of the regular conversion to new base years only if they
agree on stable-value clauses that are based on percentage changes. The Federal Statistical Office will not
confirm the mathematical accuracy of any calculations in terms of points that are made by the contracting
parties themselves.
Rebasing factors as mathematical support to facilitate a changeover to another base year have neither been
calculated nor published since 2003.
For more than one decade now, we have urgently recommended that contracts with point-based stable-value
clauses should be converted to a percentage basis and that percentage-based clauses should be stipulated in
any new contracts. This will eliminate the crucial disadvantages of point-based clauses, namely the
complicated method of calculation, results that are often difficult to interpret, and the systematic
discrimination of one contracting party.
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Annex:
Explanation of some frequently needed calculations
Calculation of the percentage change when changing over to the consumer price index for Germany
(latest adjustment prior to December 1999), including a model calculation
We want to calculate the percentage change over the period from June 1998 (reference month) to January
2013. The previously applied index is the consumer price index for a 4-person household of wage earners and
salaried employees with medium income in the former territory of the Federal Republic.
1. At first, compute the rate of change (RCh) of the discontinued index on which the contract was based up to
December 1999:
(previous index (12/1999) / previous index (reference month)) • 100 – 100 = RCh1
Example:
(round to one decimal place)
(105.2 / 104.3) • 100 – 100 = 0.9 %
"Previous index" here means the respective points level of the previously applied index; "RCh1" refers to the
percentage rate of change of the previously applied index up to December 1999.
2. In the second step, compute the rate of change of the consumer price index for Germany as of December
1999:
(current CPI (2010=100)) / CPI 12/1999 (2010=100)) • 100 – 100 = RCh2
Example:
(round to one decimal place)
(104.5 / 85.0) • 100 – 100 = 22.9 %
"CPI" here refers to the respective points level of the consumer price index for Germany; RCh2 denotes the percentage
rate of change of the consumer price index for Germany as of December 1999.
3. Calculating the overall percentage change:
((RCh1 /100) + 1) • ((RCh2 /100) + 1) • 100 – 100 = Overall percentage change
Example:
((0.9 / 100) +1) • ((22.9 / 100) +1) • 100 – 100 = 24.0 %
If you round the outcome to one decimal place, you will get exactly the same result as obtained from the
interactive program.
The indices applied in the formulas are available for free at the Destatis website at:
www.destatis.de „ Publikationen „ Thematische Veröffentlichungen „ Preise „ Verbraucherpreisindex,
Harmonisierter Verbraucherpreisindex „ Lange Reihen ab 1948.
How to calculate with annual averages?
If your contract is not based on monthly index positions but on annual averages, you will have to use the
respective annual averages for "previous index (reference month)" and "current CPI (2010=100)" instead of the
monthly values.
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