In this post I want to speak about the collection of data at a European level. Eurostat is the European institute for Statistics and it depends on the European Commission. The main goal of Eurostat is to collect comparable data from European countries, candidate countries, such us Turkey, Serbia, Montenegro, North Macedonia and Albania and also potential candidates countries such as Bosnia and Kosovo. It also collects data from EFTA countries, namely Norwey, Iceand, Switzeland and Liechtenstein. Great Britain left the union on 31st January 2021, anyway Eurostat is still collecting its data. Collecting comparable data is such a big challenge because there are many differences between countries. For example regarding crime, an action can be a crime in a country but not in another. On this matter ,UNODC, the Agency of the United Nations for Drug and Crime, is carrying on a classification of crime actions and is pushing forward the countries for using this classification, in order to collect comparable data yet at the national level. The pandemic shows us how data are important to understand phenomenons and to make better policies. Also it's evident that data must be comparable and collect whit the same criteria to be usable.