Differences between Online Prices and the Consumer Prices Index During Covid-19 in Germany

Abstract

The purpose of this paper is to examine various online price indices with the consumer price index in Germany during the Covid-19 pandemic from 2019 to 2021. This investigation refers to 9,977 items of the product category stationery and drawing supplies, whose sales prices were automatically recorded and evaluated by Amazon.de and idealo.de on a daily basis through web scraping. The official consumer price index of the German Federal Statistical Office of the 3rd Stella level is available for this product category, which makes a direct comparison possible for this study. It was found that online prices are more dynamic and volatile and react directly to external market influences than the prices of stationary trade, which are reflected in the CPI of the German Federal Statistical Office. A deviation of up to 11.7% between the calculated online price indices (OPI) and the German consumer price index (CPI) was found. Especially the value-added increase on 01.01.2021 shows a deviation effect of 9.7% to the CPI. It could be determined that the online price indices and the CPI showed the same trends, but with different characteristics. While Amazon's OPI was still in line with the CPI in 2020, deviations of over 6% were observed in 2021. The prices of other online shops already showed significant deviations from the CPI within the first lockdown in April 2021, which was imposed by the government to contain the Covid 19 pandemic in Germany and forced the stationary trade to close down across the country.