Federal Statistical Office of Switzerland

UNT / PRICE Unit

Swiss Federal Statistical Office

Espace de l'Europe 10

CH-2010 Neuchâtel

SWITZERLAND

The harmonised index of consumer prices (HICP) is a consumer price index (CPI) that is calculated according to a harmonised approach. It measures the change over time of the prices of consumer goods and services acquired by households (inflation).

Due to the common methodology, the HICPs of the countries and European aggregates can be directly compared.

European classification of individual consumption according to purpose (ECOICOP)

The HICP covers the final monetary consumption expenditure of the household sector.

The main statistical variables are price indices.

The basic unit of statistical observation are prices for consumer products.

3.6.1. Statistical target population

The target statistical universe is the 'household final monetary consumption expenditure' (HFMCE) on the economic territory of the country by both resident and non-resident households. The household sector to which the definition refers, includes all individuals or groups of individuals irrespective of, in particular, the type of area in which they live, their position in the income distribution and their nationality or residence status. These definitions follow the national accounts concepts in the European System of Accounts.

3.6.2. Coverage error population

None.

3.7.1. Geographical coverage

The HICP refers to the economic territory of a country as referred to in paragraph 2.05 of Annex A to ESA 2010, with the exception that the extraterritorial enclaves situated within the boundaries of a Member State or a country are included and the territorial enclaves situated in the rest of the world are excluded.

3.7.2. Coverage error regions

The Swiss CPI is based on the national concept while the HICP follows the domestic concept. The two indices will therefore have different weightings of their fixed basket.

The main difference between these two concepts lies in the coverage of expenditure. The national concept concentrates mainly on covering all expenditure – at home or abroad – by people residing in Switzerland, while the domestic concept focuses on covering expenditure in Switzerland, irrespective of the domicile or nationality of the purchaser. For instance, the money spent on petrol by a Swiss on holidays abroad is not covered by the Swiss HICP, whereas the money spent on the same item by an English holidaymaker in Switzerland is included.

Moreover, while the CPI confines itself solely to the expenditure of private households, the HICP also takes account of the expenditure of institutional households.

In 2017, the share of the various categories of expenditure of the total expenditure covered by the HICP is as follows:

• Expenditure in Switzerland by residents: 87.8 %

• Expenditure in Switzerland by non-residents: 5.8 %

• Expenditure of institutional households: 6.4 %

3.8.1. Start of time series

The HICP series started in January 1997.

3.8.2. Start of time series - national specifics

The first publication of the Swiss HICP is January 2008 with backdata up to January 2005.   

2015=100

The following units are used:

• Index point
• Percentage change on the same period of the previous year (rates);
• Percentage change on the previous period (rates);
• Percentage share of the total (weights).

HICP is a monthly statistics.

Harmonised Indices of Consumer Prices (HICPs) are harmonised inflation figures required under the Treaty on the Functioning of the European Union. Regulation (EU) 2016/792 of the European Parliament and the Council of 11 May 2016 (OJ L 135) sets the legal basis for establishing a harmonised methodology for the compilation of the HICP and the HICP-CT.

This regulation is implemented by Commission Regulation (EU) 2020/1148 of 31 July 2020.

Further documentation, can be found in Eurostat’s website - HICP dedicated section, namely recommendations on specific topics, under the methodology page, and guidelines, under the quality page.

None.

Regulation (EC) No 223/2009 of the European Parliament and of the Council, of 11 March 2009, on the transmission of data subject to statistical confidentiality to the Statistical Office of the European Communities.

The Federal Statistical Office is observant of the Confederati­on’s data protection laws, as set forth in the Federal Statistics Act as well as the Federal Act on Data Protection of 19 June 1992.

The names and other personal data of those supplying data are treated confidentially and used for statistical purposes only.

In line with the Community legal framework and the European Statistics Code of Practice Eurostat disseminates European statistics on Eurostat's website (see point 10 - 'Accessibility and clarity') respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably. The detailed arrangements are governed by the Protocol on impartial access to Eurostat data for users.

The HICP is released according to Eurostat’s Release calendar.

The calendar is publically available and published at the end of the year for the full following year.

The CPI/HICP release calendar can be found in FSO's website, under News / Agenda.

The HICP and National CPI figures are monthly disseminated in German, French, Italian and for some parts in English, both electronically on the FSO’s website and by e-mail (in pdf format) dissemination. CPI weighted figures are fully disseminated and HICP figures are disseminated at the two-digit level with an access to Eurostat’s HICP database for detailed results.

There is no user discrimination as regards the breakdown level. The Swiss National Bank receives the same data as Eurostat. 

Monthly

List of publications interesting the HICP :

• Harmonised Index of Consumer Prices (HICP), Overview of methods and weightings 2018, Federal Statistical Office, Neuchâtel 2018, 28 pages
• Consumer Price Index (December 2020 = 100), Methodological foundations, Federal Statistical Office, Neuchâtel 2022, 80 pages

The Global HICP index level, the change in % compared to the preceding month, the change in % compared to the same month of the preceding year and the index level of the main headings are published on the FSO Internet site at the same time as the results of the Swiss national CPI.

The HICP is published on the website of the Federal Statistical Office:

English site: Harmonised Consumer Prices | Federal Statistical Office (admin.ch)
German site: Harmonisierte Verbraucherpreise | Bundesamt für Statistik (admin.ch)
French site: Prix à la consommation harmonisé | Office fédéral de la statistique (admin.ch)

The global result for the Swiss HICP is published in the press release concerning the CPI which is issued at the beginning of the month following the reference month. More detailed results for the Swiss HICP (global index, main headings, indices and evolutions) are published at the same time on the internet site.

Both the HICP and the national CPI figures are disseminated electronically as PDF ( press release) and Excel files, which may be downloaded on the FSO’s website

HICP database.

No micro-data base access concerning the HICP.

None.

The HICP Methodological Manual provides the reference methodology for the production of HICP. (https://ec.europa.eu/eurostat/web/products-manuals-and-guidelines/-/KS-GQ-17-015)

10.6.1. Documentation on methodology - national specifics

The methodological documentation is available on the FSO website.

See also the Methodological foundations of the national CPI for more details (see the link to the English publication)

Consumer Price Index (December 2020 = 100) - Methodological foundations | Publication | Federal Statistical Office (admin.ch)

None

All the quality management system for the HICP is based on the national CPI management system. The CPI/HICP are indicators that have a large influence in the economy. An error in the CPI can have considerable financial and social repercussions. For this reason it is very important to ensure it is of good quality. That is why it is subject to very strict quality control. As no post-publication correction is provided for in the normal process, the CPI/HICP operate on a 'no error' basis. A completely documented quality system for the monthly production was introduced as early as in 2000. It outlines the quality assurance measures that are to be taken throughout the index’s standardised production process: from price collection in the different channels to the publication of results. The intensity as well as the form of the monitoring carried out at each step of the production process have been defined depending on the frequency of errors detected as well as on the risks that may arise from such errors. The system aims to achieve a total absence of errors at each stage of the process.

11.1.1. Quality management - Compliance Monitoring

Compliance Monitoring

11.1.2. Quality assurance - national specifics

Controls on the quality of the data

Checks against errors and mistakes in price information

Local and regional price collectors must check the price when they collect them. Controls concern plausibility and completeness of price collection as well as control of the item. To this effect, the tablet devices include on site plausibility checks.

Prices are checked one more time when they are entered in the central application. Prices delivered by the market survey institute are controlled by the institute as well as after delivery.

Once entered in the central software, prices are checked for plausibility. Price movements that exceed a certain percentage are checked and controlled again. Stable prices are checked as well when indicated. When needed, local price collectors are contacted again in order to confirm prices.

Finally, for calculation, aggregation is performed several times. Several control algorithms are performed on the data as a whole.

Checks against errors and mistakes in preliminary index results

Once the prices have been entered in the central application, a statement of prices that violate one of the numerous plausibility checks is generated. The team works through this list and clarifies problematic cases.

11.2.1. Compliance monitoring - last report and main results

The last available compliance or follow-up report can be found on Eurostat's web page: Quality - Harmonised Indices of Consumer Prices (HICP).

11.2.2. Quality assessment - national specifics

To ensure good quality price collections, particular attention is paid to the training and support of price collectors. A price collection manual has been created for external and central price collectors. It describes the price collection framework, the regulations regarding changes to the range of goods and deals with the areas where problems are most likely to arise. Furthermore, the price collectors are invited twice a year to training sessions during which questions and recurring problems are dealt with in detail. It should be noted that since the introduction of the price collection using touch-screen tablets, the FSO has a tool which helps avoid certain collection errors as plausibility is tested at the same time as the prices are entered.  

All prices collected undergo further controls before being validated definitively and entered in the index calculation. In addition, various control functions are included in the central price application PRESTA IT (PRESTA for PREisSTAtistik).

At the end of each production cycle and before results are published, a meeting dedicated to quality is organised to carry out a structured and documented assessment of the production and the initial results.

The FSO places great value on the quality of the information it produces as well as on its credibility and the trust placed in it by its users. In terms of quality management, it has based itself on international standards (Code of good practice and Eurostat recommendations on quality) and on the internal quality manual. The HICP also follows these principles.

In addition to being a general measure of inflation, the HICP is also used in the areas of:

• wages, social benefit and contract indexation;
• economic forecasting and analysis;
• measuring specific price trends;
• accounting purposes and deflating other series;
• inflation targeting by central banks;
• cross-country economic comparisons.

The euro area (evolving composition) index is used by the European Central Bank (ECB) as the main indicator for monetary policy management. The ECB and the European Commission's Directorate-General for Economic and Financial Affairs (DG ECFIN) use the HICP for assessing price stability and price convergence required for entry into European Monetary Union.

Other users include: National Central Banks, financial institutions, economic analysts, the media and the public at large.

12.1.1. User Needs - national specifics

The main users of the HICP in Switzerland is the Swiss National Bank, which receives the HICP data. The National Bank uses these data for internal analysis.

A larger public uses the CPI for indexation purposes. Moreover, national and international economic press, as well as academics, also count among our users.

1.1 User's satisfaction

The FSO keeps in close contact with its main users (information provision, dissemination, consultations).

1.2  Advisory Committee

For every five yearly CPI/HICP revision, an advisory group consisting of the main CPI/HICP users such as economic associations, research institutes, unions and consumers’ associations is being established to discuss the results, methodology and the planned changes, etc.

All ECOICOP indices at 4 or 5-digit level which are produced are presented in the global 'HICP Inventory Detail' annex (Excel file).

Main sources of random error: random error is impossible to analyse for most positions in the basket as no random sampling is used with the notable exception of the rent survey. In the rent survey, random error has been analysed and is of limited impact.

Systematic errors are not known.

Assessment of bias: no comprehensive analysis has been undertaken up to now.

Actions taken to reduce bias: regular resampling on point of sale level and on product level.

Rationale for not using probability sampling: absence of sampling frame. Necessity of collecting many of the important supermarket chains, which leaves little space for probability sampling in a small country such as Switzerland.

Same as Eurostat.

The full set of HICPs is published each month according to Eurostat’s Release calendar, usually between 15 and 18 days after the end of the reference month.

Each year, the January release is published at the end of February to allow for the annual update of the weights, both of individual product groups and the relative country weights of Members States in the country group aggregates.

The euro area flash estimate is published on the last working day of the reference month or shortly after that.

Since the March 1997, launch of the HICP release, the HICP for the country groups aggregates has always been published on the dates announced in Eurostat’s Release calendar.

HICPs across Member States aim to be comparable. Any differences at all levels of detail should only reflect differences in price changes or expenditure patterns.

To this end, concepts and methods have been harmonised by means of legislation. HICPs that deviate from these concepts and methods are deemed comparable if they result in an index that is estimated to differ systematically by less than or equal to 0.1 percentage points on average over one year against the previous year (Article 4 of Council and Parliament Regulation (EU) 2016/792).

Switzerland has adopted these concepts and methods since the first publication of its own HICP in 2008.

HICP data are fully comparable over time. There have been several improvements in methodology since the HICP was introduced with the aim of improving its reliability and comparability. These changes may have introduced breaks in time series. However back calculations under the newer standards were performed when appropriate basic data was available.

Differences between the HICP and national CPI

• Differences in the geographic and population coverage:
  • The HICP is based on the domestic concept while the CPI is based on the national concept
  • The HICP covers the collective households, which are excluded from the CPI.
    
    
• Prices for package holidays and passenger transport by air:
  • Prices for package holidays and passenger transport by air enter into the HICP calculation for the month in which the consumption of the service at the observed price can commence. They enter into the CPI calculation for the month in which they are observed (acquisition concept).
    
    
• Consumption expenditures included in the HICP, but excluded from the CPI:
  • Consumption expenditures of non-resident households in Switzerland
  • Consumption expenditure of institutional households
    
    
• Consumption expenditures excluded from the HICP, but included in the CPI:
  • Expenditure for owner-occupied housing
  • Expenditure for games of chance
  • Consumption expenditures of domestic households abroad

The HICPs are internally coherent. Higher level aggregations are derived from detailed indices according to well-defined procedures.

Not available

The HICP series, including back data, is revisable under the terms set in Articles 17-20 of Commission Implementing Regulation (EU) 2020/1148.

17.1.1. Data revision - policy - national specifics

The Commission Regulation (EC) No 1921/2001 on revisions (repealed and replaced by Commission Implementing Regulation (EU) 2020/1148, Articles 17-20) was implemented in the Swiss HICP in 2008.

The revision policy is however not to revise the Swiss HICP once it has been published except in case of big errors in the data or great methodological change which would have an impact on previous years.

Revisions of HICP consist on renewing the weights (annually in December).

In addition, the new regulation on seasonal products is being applied to the HICP since 2012 (with 2011 backdata).

One revision of the results had to be made for the year 2015 following the implementation of the new reference base year (2015=100).

Moreover, since then, the two decimals publication policy has been applied for the Swiss HICP.

In 2017, the HICP-AP has been introduced.

In 2021, as a consequence of the 2020 CPI/HICP revision, new items has been added or deleted from the standard basket of gods and services (see global 'HICP Inventory Detail' annex (Excel file)).

18.1.1. Weights

As the HBS is conducted annually, the basket of weights has been updated every year since 2002 (for the CPI), making it possible to take fast account of changes in household consumption habits and to have weights that more closely reflect the actual consumption patterns of private households.

To obtain the final HICP / CPI weights used in year t, a price-update is made between the HBS year (t-2) and the HICP / CPI reference period (December t-1) in order to ensure consistency between the base period and the reference period (for which weights are valid). To do this, the weights of each expenditure item calculated using HBS t-2 are adjusted using the price developments in these same expenditure items between t-2 (using annual average) and December t-1.

For example, to calculate weights for December 2019, HBS results from 2018 were adjusted to take into account price changes between 2018 (annual average) and December 2019.

As the HICP’s geographic coverage is defined according to the domestic concept, it is not possible to base the weighting of the Harmonised Index solely on the Household Budget Survey (HBS), as can be done for the CPI, which is defined according to the national concept and contains no information about expenditure in Switzerland by non-residents. Moreover, the CPI excludes all information about expenditure by institutional households, more specifically by the inhabitants of medical and social institutions.

As these two categories of expenditure are covered by the HICP, different sources – from the highest to the lowest level of aggregation – have had to be identified in order to arrive at the weighting for the Swiss Harmonised Index of Consumer Prices.

Sources for the highest level of aggregation

The total of the household final monetary consumption expenditure (HFMCE) is provided every year by the National Accounts (NA). 

Three main sources are used to identify total expenditure by origin and the type of household under consideration:

• The Household Budget Survey (HBS) is used to identify expenditure by residents in Switzerland. The HBS findings for year t-2 are used to weight the HICP for year t.
• The Tourism Balance of Payments makes it possible to identify expenditure in Switzerland by non-residents. The findings of the Tourism Balance of Payments for year t-2 are used to weight the HICP for year t.
• The Health Statistics make it possible to identify the expenditure of inhabitants of medical and social institutions. The statistical data for year t-3 are used to weight the Index in year t. Furthermore, these Statistics publish cost movement estimates which are used to adjust the figures for year t-3 until year t-2. The expenditure of administrative households and those employed in hotels and medical and social establishments can be identified thanks to the Household Budget Survey (HBS).

The weights for the regions are updated every 5 years, using a 5-year aggregate model from the HBS. The weights for the outlets are updated every five years too, using data from market research institutes.

Note that weighting is being revised as from 2024 in order to comply with HICP regulation.

Note that the changes due to the pandemic are explained in detail in subsequent points: 'Compilation of sub-index weights', 'Reference period higher levels' and 'Price updating'

18.1.1.1. Compilation at elementary aggregate level

Once identified, the total expenditure for each of the categories under consideration has to be distributed over the various ECOICOP categories. This task is comparatively easy as regards the expenditure of residents in Switzerland since they are compiled on a very detailed level by the HBS.

For expenditure by non-residents, institutional households and particular products, weighting is done by type of 'visitor' or type of source. 

a. Expenditure by tourists and day-trippers is evaluated according to the Tourism Balance of Payments information (accommodation and meals) and to the public transport turnover. However, these two sources do not permit full distribution of this expenditure. The remainder is weighted using the HBS (by residents’ consumption expenditure abroad).

b. The expenditure of cross-border workers is weighted according to the HBS, on the accepted assumption that their consumption habits are comparable to those of the resident population, with the obvious exception of expenditure on housing.

c. Much of the expenditure on financial services (bank charges) is generated by non-residents, they have to be included in the HICP. The appropriate weighting data are derived from the National Accounts. No distinction is made between the expenditure of non-residents and that of residents. Only the expenditure of private households is taken into consideration.

d. Expenditure of institutional households is weighted according to the Health Statistics for the inhabitants of medical and social institutions, and according to the HBS for administrative households, employees of medical and social institutions and hotel staff accommodated by the employer.

e. For tobacco, HBS data are replaced with data from another reliable source. Since 2013 (2016 for the CPI), information on tobacco duties lev­ied by the Federal Customs Administration is used to determine household spending on tobacco items. This decision was made on the basis of the probable underestimation of consumption expenditure on tobacco products in the HBS

18.1.1.2. Compilation of sub-index weights

The household consumption expenditure data in t-2, i.e. those for the year 2021, are not representative at all of the year 2022 (t-1). The impact of the pandemic has profoundly changed consumption patterns in many sectors.

Under these circumstances, the usual practice of using t-2 data was impossible. Instead, the FSO was able to use data from the year 2022.

As every year, the main basis for the weighting is the Household Budget Survey (HBS) completed by the tourism balance (provided by the National Accounts) and the statistics of public health.

We have been able to benefit from the latest provisional data provided by the HBS for the period from December 2021 to November 2022 for all the weighted items in the Swiss HICP consumer basket.

The analyses have shown their good quality as well as their excellent results in areas as sensitive as package holidays, catering and airfares.

However, they have been corrected by external sources in two areas: new cars (data supplied by specialists) and, as usual, tobacco (data supplied by the customs administration).

For the tourism balance, we have only had the 2021 data from the National Accounts at our disposal. These data have been corrected by external sources in the accommodation sector (information supplied by specialists).

As the HBS data runs until November 2022, two thirds of the fourth quarter of t-1 has been covered. The month of December was considered to be covered by the use of the price update (see point 18.1.1.5).

18.1.1.3. Compilation of sub-index weights

Like the CPI, the HICP is calculated as a Laspeyres chain index which weighting is adjusted annually to take account of changing consumer habits and to keep abreast of the current situation.

The 2023 weighting of the fixed HICP basket is based on the data from the various surveys whose take the pandemic economic effects into account, namely:

• 2021 National Accounts (T-2, provisory data), corrected by the 2022 estimation based on the economic forecast by Federal Governments' Expert Group (see 18.1.1.6)  

• 2022 Household Budget Survey data (from December 2021 to November 2022)

• 2021 Tourism Balance of Payments data (t-2) with correction in some sectors (see previous point on the 'Compilation of sub-index weights')

• 2020 Health Statistics data (T-3) 

18.1.1.4. Weights – plausibility checking

The Household Budget Survey (HBS), conducted every year by the FSO among private households with permanent residence in Switzerland, is the main source for weighting the CPI / HICP components.

The HBS is considered the best source of information for weighting the basket of goods and services because:

• It covers all private household consumption expenditure;
• Its results are recent, with a time lag of only two years. For example, 2019 weights were calculated using HBS findings from 2017;
• It uses the same ECOICOP classification as the HICP / CPI;
• It offers indications regarding data reliability (coefficients of variation);
• It can be scaled to the specific needs of the HICP / CPI and provides results with a high degree of granularity.

The HBS is conducted using a randomised sample selected from the population survey sampling frame and stratified by the seven major regions of Switzerland. The randomly selected private households are interviewed about their daily, regular and irregular expenditures during the month in which they are participating in the survey as well as about their income. The period of observation is extended to the past 12 months, which results in more observations and lower variance.

HBS data are analysed specifically for the HICP / CPI, tested for reliability and analysed, only after which do they serve as the basis for weighting the basket of goods and services.

18.1.1.5. Price updating

As Switzerland was able to benefit from the HBS data for the year 2022 (t-1), there was no need to perform a price update between t-2 and t-1. Nevertheless, in order to be as close as possible to the definition of a Laspeyres-type index, a price update was performed up to the month of December 2022.

The update factor is the relation between the index of December 2022 and the annual average from December 2021 to November 2022, the period surveyed by the HBS. As can be expected, the impact on the result of the weighting is minimal.

The price update has been done at all weighted items levels.

18.1.1.6. Compilation of total household final monetary consumption expenditure

Country weights (HFMCE, etc.) data are delivered by National Accounts. The 2021 data were used and then corrected by the estimation in nominal values based on the economic forecast by the Federal Government's Expert Group - December 2022 (State Secretariat for Economic Affairs SECO).

Data such as OOH, FISIM and games of chance have also been adjusted for the year 2022.

The forecast of the expert group is valid for the entire year 2022 and therefore includes the fourth quarter of t-1.

18.1.2. Prices

Decisive for calculating the CPI/HICP are transaction prices, i.e. the price paid by consumers for a specific good or service, including indirect taxes (chiefly VAT and incentive fees), customs duties, environ­mental taxes and subsidies. Credit or interest costs are not taken into account.

18.1.2.1. Data Source - overview  

See Excel file, under 'Annexes'.

18.1.2.2. Scanner data - general information

As early as 2008, price data from major retailers started being collected in part through scanner data. The price collection with scanner data is managed by the FSO. This improved way of collecting prices is likely to be extended to other retailers and assortments in the coming years.

The data in this instance is obtained by using in Switzerland the in-store code numbers. It contains important information for consumer price statistics and has led to a strong qualitative improvement in the index. Since the turnover generated by each item is known, it is possible to select the bestselling goods using objective criteria, then calculate the price actually paid by consumers for a given item during the month. This is done by averaging data for the first two weeks of the month.

We are currently using the scanner data of four supermarket chains which accounted for about 75% of sales on food, household detergents and personal care products. In terms of HICP weights, scanner data accounts for 10% of the weight of the Swiss HICP (and also of the Swiss CPI) and is used in ECOICOP headings 1, 2, 5, 9 and 12. Since 2021, some near food prices and fuel and diesel price are collected for one of the biggest retail chain. The work is ongoing for 2021 and the following years.

18.1.2.3. Web scraping - general information

Switzerland uses web scraping on a small scale for certain outlets.

Web scraping is legal in Switzerland. However, enterprises may block scraping, There is not yet a legal basis to force them to accept scraping by the NSI.

However, some prices of chosen items are collected by using web scraping :

• ECOICOP 03 clothing: 800 prices pro month (9-10% of all the prices collected for the group) 
• ECOICOP 05 (Household furniture): 200 prices per month (1% of the prices collected)
• ECOICOP 07 tyres: 1 000 prices for the year (16% of the prices surveyed)
• ECOICOP 09 books: 20 400 prices (7% of the prices surveyed)

2.6% of all the prices in the standard basket of goods and services are collected using web scraping.

8 websites (outlets) are monthly webscraped up now, 3 for the clothing, 1 for household furniture, 1 for tyres and 3 for books.   

18.1.3. Sampling

18.1.3.1. Sampling design: locations for survey

The basket of goods and services contains all the goods and services considered to be representative of the consumption expenditure of private households. It covers a wide range of prod­ucts, from food, clothing, housing and furnishings to healthcare services, transport and communication.

Though exhaustiveness is a definite aim, it is not practical to survey the prices of every single product or service on the mar­ket because consumers have access to an innumerable range of offers.

Choices therefore have to be made, largely on the basis of three criteria: the importance of the products in private household consumption expenditure, the existing statistical series and the effort which has to be made to collect prices. The following goods and services are included in the baskets of goods and services:

• those accounting for at least 0.1% of the private consumption expenditure (this corresponds to an average expenditure of CHF 6.– per month and household).
• those being part of existing series in the current CPI/HICP. As a rule, series are maintained even if their weighting is temporarily less than 0.1% of the private consumption expenditures.
• those that can be collected without an excessive workload.

Products and services accounting for less than 0.1% of the private consumption expenditures are generally not included in the basket of goods and services (for instance the renting of du­rable goods or the funeral services). An exception is made in the case of some staples, such as rice, flour, tea, and certain fruit and vegetables, which, despite their slight importance for household expenditure, are nevertheless part of the basket of goods and services. This choice is justified by the historical continuity of the statistical series and by users’ interest for this kind of products.

The main source used to construct the basket is the House­hold Budget Survey (HBS), which provides highly detailed infor­mation about the consumption expenditures of private house­holds and their importance. Data from associations, distributors and market research companies with experience in the various markets concerned are also used.

The basket of goods and services is updated every time the index is revised. This consists of updating the sample of prod­ucts whose prices are collected as well as expenditure items for which indices are released. For example, the 2020 revision introduced data collection on Hire of private means of transport, public transport abroad, passenger transport by ship, recreational boats, museums and zoological gardens, services of lawyers and more besides.

Table : Example of the hierarchical structure of the basket of goods and services

Once the products have been selected, a structure has to be defined. This is important in order to classify the products as coherently as possible and to provide aggregated results, which match user needs. The international classification COICOP has been used since 2000 for the national CPI and since its implementation in 2008 for the Swiss HICP; all European countries apply this clas­sification to calculate inflation and for other surveys. It allows international comparison of the detailed results for the twelve main groups and jointly defined product groups.

Expenditure items are found at the lowest level of detail, fol­lowed by varieties (see Table above). In 2015, the basket of goods and services was adapted to comply with ECOICOP down to the ex­penditure item level. Varieties are defined nationally depending on spending patterns in each country. The upper strata of the basket of goods and services must preferably be kept unchanged between revisions, but varieties can be adapted annually

18.1.3.2. Sampling design: outlets

Sales outlets offering products found in the basket of goods and services are selected in each region. The index contains both ma­jor sales outlets established nationwide and regional sales outlets, which are chosen by regional price collectors in consultation with the FSO. In all, approximately 5 000 sales outlets participate in the successive surveys. Most of the sales outlets are grouped in distribution channels, which are in turn weighted according to the consumer expenditure of private households. The sales outlets sample is permanently updated, in line with outlet market development.

18.1.3.3. Sampling design: newly significant goods and services

The basket of goods and services is updated every time the index is revised. This consists of updating the sample of products whose prices are collected as well as expenditure items for which indices are released. For example, the 2020 revision introduced data collection on Hire of private means of transport, public transport abroad, passenger transport by ship, recreational boats, museums and zoological gardens, services of lawyers.

Price data is collected every month.

18.3.1. Price collection surveys

Organisation of the price collection

The price collection is structured at three levels: regional, sales outlets and the products themselves.

At each of these levels, a representative sample of the total population is constructed. With the exception of rents, sampling frames are not reliable enough for random selection. Hence, in all other areas, sampling is non-random.

The price collection is divided into two categories

• A regional collection is conducted in the 11 selected regions. It concerns only part of the basket of goods and services, namely products whose prices are set at regional level, such as fresh products and petroleum products for instance. This regional collection guarantees the presence in the sample of regional sales outlets such as bakers, butchers and specialised shops. Regional price collectors also collect data at selected retail chains. As these prices undergo the same shifts nationwide, they can be collected in any region. Since 2000, regional collection work has been contracted out to a private market research institute, which has a network of 40 regional price collectors who collect prices in about 1 000 sales outlets. These regional collectors live in the region they survey and are familiar with its commercial structure and local consumer habits. Their work is regularly monitored by the mandated institute and by the FSO, and they are given training twice a year which makes it possible to constantly upgrade the quality of their work and to standardise collection practices (especially as regards quality adjustments).
• A central collection is carried out mainly by the FSO. It concerns groups of products whose prices are administered or semi-administered (for instance, health and public transport), products whose prices are identical throughout Switzerland (such as telecommunications) and major distribution chains whose prices are set at national level. The FSO collects prices in more than 1 700 sales outlets. Moreover, rents are collected with about 2000 real estate managements.

Notes:

[1] The major regions are superregional areas established in 1997 for the purpose of regional and international statistical comparisons. They are the Lake Geneva region, Espace Mittelland, North-Western Switzerland, Zurich, Eastern Switzerland, Central Switzerland and Ticino.

[2] Regions’ weights are adjusted every five years, in connection with each CPI revision. To ensure the representativeness of the findings over a relatively long period and for smaller regions, the averages of HBS data between 2016 and 2018 are applied.

18.3.2. Timing of price collection

Since January 2008, the prices of most products have been collected on a monthly basis. Exceptions are:

• Goods and services whose prices have been shown to change less frequently. These prices are collected on a quarterly basis (e.g. rents)
• Seasonal products for which the collection months are determined by availability
• The prices of products for which pricing changes are known in advance and broadly communicated (e.g. postal services and public transport) are surveyed aperiodically (when they change).  

The prices of the selected items are surveyed in the first two weeks of each month. Given their sharp fluctuations, the prices of petroleum products (heating oil and fuel) and airfares since 2021 are surveyed twice a month (based on set days, at the beginning and middle of the month). Price data for fruit and vegetables are partly collected over the first week and partly over the second week of the month.

Annex: Frequency of survey: 

• Services for provision and maintenance of the housing: half-yearly, in March and October
• Electricity: yearly, in January
• Gas: monthly
• Communications: monthly
• Insurance: yearly, in January

Data validation is done by FSO; additional quality checks are carried out by Eurostat.

18.4.1. Data validation - price data

Quality assurance system for the CPI/HICP production

18.5.1. Elementary price index formulae

The Swiss HICP is a Laspeyres-type index,as the Swiss CPI.

The index and the weights are published at two decimals, rates of change at one decimal.

Price observations are not delivered to Eurostat. 

For more detailed on the index formula and the aggregation, see the annexed document.

18.5.2. Aggregation of different data sources

See 18.5.1 'Index formulae' and its annex.

18.5.3. Chaining, linking and splicing methods

See 18.5.1 'Index formulae' and its annex.

18.5.4. Quality adjustment – Detailed information

All the details for replacement and quality adjustment are in the annexed file.

18.5.5. Seasonal items

Since 2011, Regulation(EU No. 330/2009 concerning seasonal goods, repealed and replaced by Commission Implementing Regulation (EU) 2020/1148), was intended to standardise the methods used for processing this category of goods between the European Union (EU) member countries. The Eurostat regulation eliminates the influence of products that are unavailable in the index by imputing, out-of-season, the trend of a similar good surveyed or of aggregates of similar goods for which prices are collected all year round. For the Swiss HICP, this method is used for the following groups of products (ECOICOP):

• 01.1.6 Fruit
• 01.1.7 Vegetables
• 03 Clothing and footwear

The results from recent years confirm what was expected (greater variability for the groups directly affected by the HICP regulation). For the CPI, European legislation has not been applied in this area. The last price collected in season is thus imputed over the entire out-of-season period. This leads to less seasonal variation.

The advantage of the method used in the HICP is that out-of-season products do not have any impact (or at least only little impact) on the results. The disadvantage of this method is that purely imputed variations that have nothing to do with the monetary reality (e.g. inflation on strawberries in winter) are introduced.

Not applicable.

None.