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Price indexes


Measurement of price indices, in particular the monitoring of price movements of some products, which are used in most households, as well as development costs incurred by families with the purchase of these products.

Measurements of changes in prices, showing retail prices and price changes of some (mainly technical) products through a period (months). The product range is based on assumptions, what are the typical products of the average household in the world. Product selection is limited, which UniWorldCat compares rates.

Data collection method:

Data on prices of goods in electronic UniWorldCat collected every day, because the majority of prices sent traders themselves. Around 320 traders regularly (daily) sent the price of goods from some other major retailers, the prices obtained by other methods. This is achieved purely objective price collection of goods traders from all over the world. Monthly so as to calculate the average rates of 40 kinds of products included in the measurement around 250,000 or 420,000 individual prices for the products.

Choosing to change the calculation of price indices includes 40 products. Featured products are those which have the most significant (large) share for the average family. Product range also includes products from the areas of: Audio-video, computer, photo, home appliances, phones and car accessories. All product information and prices are always based on UniWorldCat.

Price trends and indicators depend not only on the actual prices of individual products but also about the current state of the market. It is normal that the sale is not always the same products with the same features, but offer various types of products change over time due to the nature of the products, which are constantly changing and improving technology. This can lead to deviations from the average value calculated rates. Product Catalog measured this way, you can change monthly merchants change over time their sales programs. However, the measurement of the state of the price for one month is an important indicator by which the consumer can see exactly where price move limits for each type of product.


Products are grouped into six major categories:

Audio & Video: TV, stereo, MP3-player, DVD-player, DVD-recorder, home cinema.

Computers monitor, laptop, mouse + keyboard, multi-function laser printer, an inkjet printer, a PC / video game console, a USB key

Photo: digital camera, memory card camcorder.

Household appliances: washing machine, dishwasher, stove (hob + oven), extractor hood, fridge, freezer, toaster (toaster), blender, appliance for baking bread, microwave, hair dryer, vacuum cleaner, iron, hair dryer, shaver, epilator.

Telephony: landline phone, GSM phone, headset.

Car equipment: summer tires, winter tires, light alloy wheels.


1. Measurement: it covers 20% of the price of the most viewed articles of each product category.

2. Measurement: it covers 20% of the price of the cheapest products of each category of products.

From these measurements is formed, all data contained in the press release and the measured price trends.

The overall price index, and the other in a public statement published price changes for individual products are derived from the average of 20% of the most popular and 20% cheaper than similar products on the UniWorldCat.

The trend is calculated by linear regression using the daily prices for the selected period.