kolmy said:
How did I see that a country have a better economy that other one?
Either press F6 (or click on the book/ledge) and then click through the various pages with info such as wealth or trade tech of the important countries.
or press F12 to bring up the console and type info and the abbrevation of the country in question, e.g. info HAB (for Habsburg/Austria) or info TYR (Tyrol) to get a short overview.