In economic statistics, the shopping basket is a representative computational compilation of various goods and services for the purpose of determining the price index as well as inflation and deflation . The price development of the goods and services included is determined over a certain period (e.g. four years) with constant weighting of the individual items.
Usually, the shopping cart is understood to be the calculation basis for determining the consumer price index (CPI). This takes into account the proportional expenditure of private households for the corresponding goods and service categories. There are also shopping baskets for calculating other price indices such as producer price index , wholesale price index or construction price index .
Shopping cart in Germany
|01 Food, soft drinks||13.1||10.3||10.4||10.3||9.7|
|02 Tobacco products, alcoholic beverages||4.2||3.7||3.9||3.8||3.8|
|03 Clothing, shoes||6.9||5.5||4.9||4.5||4.5|
|04 Housing, water, gas, fuel||27.5||30.2||30.8||31.7||32.5|
|06 Health, care||3.4||3.5||4.0||4.4||4.6|
|09 Leisure, culture, entertainment||10.4||11.0||11.6||11.5||11.3|
|11 hotel, restaurants||4.1||4.7||4.4||4.5||4.7|
|12 Other goods and services||6.1||7.0||7.4||7.0||7.4|
|Source: Federal Statistical Office|
In Germany, the shopping basket for the consumer price index is created by the Federal Statistical Office and contains around 650 goods and services (as of 2018).
The database for determining the consumer price index is created through monthly surveys: Every mid-month, around 600 employees carry out price surveys on the goods and services in the shopping cart on behalf of the State Statistical Offices and another 20 on behalf of the Federal Statistical Office. The prices are requested from so-called reporting units (e.g. retail stores, service offices, etc.), which are distributed across the whole of Germany.
To calculate the consumer price index, more than 300,000 individual prices are manually collected in retail and service companies every month. This price survey, which has been customary up to now, includes on the one hand the decentralized price collection by price collectors in shops throughout Germany and on the other hand the central price collection, which is mainly carried out as a survey on the Internet. The additional use of digital data sources enables the statistical offices to significantly increase the number of monthly price observations.
The weighting scheme, which weights the individual items and prices according to their share of household expenditure, is updated in Germany as a rule every five years.
Aspects of the shopping cart model
There are various problems with the shopping cart model that can lead to a deviation in the calculated inflation rate / inflation rate .
More performance in the shopping cart
Products are improved over time due to technical progress . Take the car, for example: simply equipped car models are disappearing from the market. New models have built in things that were reserved for the most expensive luxury-class models 20 years ago: ABS, airbags, ESP, automatic air conditioning. Overall, in many areas of life, increases in prices can be explained by development and progress. An increase in prices is thus observed, which is partly based on a higher standard of living, increased demands or increased legal requirements.
However, it can also happen that the product quality deteriorates over time, for example due to increased consumption of water or electricity in household appliances or fuel in cars. The statistical offices use this method to take such quality effects into account and to determine the "pure" price change called quality adjustment procedures, for example the hedonic method or the use of option prices. This does not change the shopping cart itself.
Adjustments to the shopping cart
Since consumption habits change over time, the shopping cart must be adjusted regularly. This weighting must reflect the actual consumption quantities of the residents.
Different shopping carts for different purposes
Different shopping carts have to be defined for different purposes. While a shopping basket that is as representative as possible is chosen for measuring inflation, it often makes sense to work with special shopping baskets when analyzing the causes. A core inflation rate is determined by removing food and energy prices from the shopping cart.
Consumption habits differ according to age, household size, region and lifestyle. For this reason, the change in the price level determined with the help of a shopping cart does not reflect the individual spending situation. Therefore, shopping baskets for different household sizes are determined in order to measure the effects of inflation on individual population groups.
Citizens' perception of inflation is not equally shaped by price increases for all goods. Changes in the price of frequently purchased goods are more noticeable to buyers. Hence the term " perceived inflation " came about . In order to measure this, a shopping basket is defined, which gives higher weighting to everyday goods (e.g. groceries) that are bought frequently.
According to the website of the official Austrian statistics agency, the perceived inflation is ".. the extent of the inflation that every person intuitively feels when shopping on a daily / weekly basis. Because the prices for short-term purchases have risen above average in recent years, the feeling of being substantial arises higher inflation than officially reported (phenomenon of "perceived inflation"). Statistics Austria does not calculate an indicator for perceived inflation, but it does show the rate of price increases for daily or weekly shopping (see micro and mini shopping cart) ".
Shopping cart in Austria
In Austria , the shopping cart for the consumer price index is compiled by Statistics Austria . From 1966 to 1996 the shopping basket was updated every ten years (CPI 66 to CPI 96). Based on specifications from Eurostat , the shopping basket is now adjusted every five years. The current CPI is 2015, the next update will take place in 2020, the new index series will be published from January 2016. The shopping cart includes cereal products, meat products, fish, milk, cheese, eggs, fats, oils, fruits and vegetables including potatoes.
Shopping cart in Switzerland
In Switzerland , the Federal Statistical Office runs the national index of consumer prices (LIK). The percentage composition of the goods contained in the shopping basket has been updated annually since 2000 by the Income and Consumption Survey (EVE) in the individual households. The shopping cart contains not only groceries, but all household expenses such as rent, energy costs, etc.
Shopping cart in the UK
In Britain, the cart is ( English consumer price basket ) for the consumer price index is also calculated (CPI) based on a representative basket of goods.
Shopping cart in online trading
In online trading, shopping cart is the name of a virtual clipboard that collects the previously planned purchases before the order and payment are made. When the product is placed in the shopping cart, the transition to the purchase phase takes place, which starts when an order button is pressed . The shopping cart should be able to accommodate, delete and put back ( reservation ) several articles ; It is also expected that the shopping cart contains the purchase price , VAT , shipping costs and possible payment methods .
- Information from the Federal Statistical Office on the shopping basket and weighting scheme (as of August 2016)
- Federal Statistical Office (Destatis): Consumer price index for Germany
- Consumer price index for Austria
- Consumer Price Index (Switzerland)
- Shopping basket and weighting (Switzerland)
- Revision of the consumer price index 2008
- Shopping basket Austria 2005 (PDF; 107 kB)
- see also the article in the English Wikipedia
- Gerrit Heinemann, Der neue Online-Handel , 2018, p. 105