I would look at a "happiness index" if you want to find out which countries are performing well because it will generally align with them thinking that the government takes the right decisions. There are countries like Norway or Saudi Arabia that have a lot of money raised from oil, that are able to put it to good use in the best interests of the general public - although Norway is a lot better at thinking long term. Most European countries would sit in the medium the high bracket for reasonable spending of public taxes. The smaller a country is, the easier it should be to manage and put money to use most effectively. However the larger a country, the easier it should be to wield considerable cost efficiencies and buying power.