The Country Similarity Index attempts to quantify how similar countries are to each other relative to other countries. The index is a statistically-based way to measure this. It weighs equally five major aspects of countries: their demographics, culture, politics, infrastructure, and geography. The methodology is exactly the same for each country.
The data from the Country Similarity Index was used to cluster European countries into different regions. This resulted in 7 distinct regions and 12 sub-regions.
Hopefully, this graphic will help people understand the similarity of European countries relative to each other better than a traditional map, which only shows geographic adjacency. This shows other political, cultural, demographic, and technological adjacencies that a physical map of the world does not account for.
The logic of the connected web is as follows: each country is connected to its most similar country and also the next most similar country that is not more similar to the countries more similar to the country. For example, Denmark’s most similar country is Norway. However, its next most similar country, Sweden is more similar to Norway than Denmark. The next country that is more similar to Denmark than Norway is Germany. Therefore, Denmark is on a spectrum somewhere between Norway and Germany.
In reality, the web would need to be three dimensional, since there are limits to what can be shown clearly on a two dimensional graphic. In order to fit all the connections on a two dimensional web, it was necessary to break some of the lines. For example, Luxembourg is on a spectrum between Belgium and the Czech Republic. Furthermore, some connections are not shown on the map if the country already has two connections. For example, Croatia is disproportionately more similar to Italy than any other Slavic country. However, since Italy is between France and Spain while Croatia is between Slovenia and Serbia, this connection ends up not being shown.
Please keep in mind that just because some countries are close to each other on this graphic, does not necessarily mean they are very similar to each other. For country specific questions, it is best the consult each individual country’s page on this site. Only the lines connecting countries are meaningful, not their location on the graphic. For example, although Norway and Slovakia are next to each other in the graphic, no lines are between these countries, so no relationship is necessarily implied. The thicker the line, the closer the similarities between the countries are.