Price statistics
A Price Statistics provides statistical information on rates in the studied this economic field. Price statistics are primarily created in the official statistics .
Determination of average prices
The availability of price statistics in the form of average prices is important in order to derive new knowledge over time or in a regional or specialist cross-section. However, price statistics are rarely presented in the form of average prices. This is due to the very high requirements and the associated high costs . In addition, there are delimitation problems which, with the help of relevant legal standards, e.g. B. be resolved from food law. Furthermore, the production capacities are subject to the passage of time, so that the comparability of prices for different periods is only possible to a limited extent.
Example: If the average price for bread in different regions for different business categories is determined over time in a country, the price ratios for bread for different regions or for different business categories as well as the price ratios between different time periods could easily be derived from this. Demarcation problem when determining average prices: What is the demarcation between "bread" and "rolls"? Depending on the decision, the average price of bread is significantly reduced by a small bread or that of a bread roll is significantly increased by a large one.
Determination of price indices
In the case of price indices , the sample model is less critical in comparison, since it is assumed that the products in a product category are in a competitive relationship and therefore develop similarly in terms of price. The products in a product category are much more similar in terms of price development than in terms of price level.
Example: Even if white bread is cheaper than sunflower bread, their prices are likely to develop relatively similarly.
Because of these lower requirements, price indices are usually presented as a statement about price development over time in an economic sector. It is characteristic of real price indices that they only make a statement about the development of prices over time. The observed good does not change in the model. If the prices of the observed goods change over time because their utility value improves to the same extent (e.g. as a result of technical progress), the price indices remain unaffected. The prices for a given utility value (“quality”) have not changed in this case.
shopping cart
The basis of the price statistics is the creation of a shopping basket with goods representative of the economic sector examined. In addition to the composition of the basket, the importance (weight) of the individual goods in the basket must also be determined (weighting scheme).
In the consumer price index for Germany (CPI), for example, the shopping basket consists of goods that private households buy for their own consumption. For the composition and the structure of the shopping cart z. For example, with the European " Harmonized Consumer Price Index ", the COICOP classification is mandatory by means of an ordinance .
The shopping cart is also the starting point for determining survey items. These are the specific goods whose sales price is charged.
Example: For bread, a survey item could be “Mixed rye bread”. The fact that the proportion of rye flour is at least 60% results from food law regulations.
For the specified survey items, prices are regularly collected in the price statistics. To do this, it must first be determined who should (or must) report the prices to the price statistics.
Selection of reporting units and specification of the survey items
Since it is practically impossible to first get an overview of the sales in an economic sector and then to collect prices, the price collection is carried out continuously from representative selected economic actors who regularly carry out such transactions (on the buyer's or seller's side) Third parties based on legal regulations - e.g. B. Notaries in the case of property transfers or customs authorities in the case of import or export of goods - knowledge of such transactions and can thus potentially be selected as reporting unit. The selected economic actors are assumed to have their pricing representative.
In price statistics, a formal random sample selection is unusual, as the requirements for the reporting units are not covered by the available selection bases: It is not known a priori whether a selected reporting unit will make sales in accordance with a given survey item. If this is the case, the reporting unit must complete the description of the survey item (see above). Furthermore, demanding information must be provided in the course of the price survey (see below). Some reporting units cannot meet these requirements. Therefore, after pre-selecting a (potential) reporting unit, an attempt is made to clarify whether these prerequisites are met before it is actually used for reporting and thus for a factual selection.
Price collection and processing, processing
Once the specific goods have been determined for a price survey, regular price surveys can be carried out for this purpose by asking the reporting units monthly or quarterly - depending on the price statistics - at what price they are selling the survey item in the variant (see above) on the reference date or within a have sold for a certain period of time.
If a good was not sold or not sold in the specified variant, the price development for a similar good that was sold both in the previous and in the current period is usually used as an indicator for estimating the price charged.
If a good is no longer sold at all, the price survey must be transferred to a similar good that also fulfills the specified requirements. Such transitions and generally the effects of structural change in the goods sold (technical progress) require a so-called quality adjustment so that price indices can be calculated that reflect the "real price change" (see above).
Once the prices have been collected and checked for plausibility, the index can be calculated .
Applications of the results
First of all, the results of the price statistics, namely the price indices (for a time comparison), are generally used to monitor the economy . In a boom phase, prices tend to rise, while in a recession they stagnate or even decline - usually only partially. However, price indices are only of a supplementary nature for economic monitoring, as they lag behind other economic indicators.
Price indices are far more important for assessing the relationship between supply and demand in an economic sector. If the price indices show developments in a politically undesirable direction, they can give rise to counter-directed political measures. Particular attention is given here to the price development, which is reflected in private households and measured in the consumer price index , since ultimately all price trends in an economy are reflected in a more or less long delay in purchase by the end consumer (private households). This price index is therefore generally used as a measure of inflation in an economy. Accordingly, measures of financial policy and above all monetary policy are linked to the development of this price index.
Another important function of price indices is their use in capital preservation clauses . Here, contractual partners secure themselves for later cash payments by basing them on current price or cost ratios. If these conditions change in the future, the payments are to be adjusted in the same ratio, measured against fixed price indices. A typical example of this is a contractually agreed index rent .
An important internal statistical function of price indices is the deflation of economic data. The statistical data available in the current prices are adjusted for the inflation share. This allows the determination of "real" data.