The Prosperity Index ranks countries according to their performance across eight equally-weighted sub-indexes. The 2015 rankings reveal the most and least prosperous in the world. Norway ranks 1st gloablly in the 2015 Prosperity Index, having kept its place for 7 years. The U.S. dropped out the top 10 to place 11th. The 10 overall rankings in 2015 are Norway, Switzerland, Denmark, New Zealand, Swenden, Canada, Australia, Netherlands, Finland and Ireland. China ranks 52th in the overall rank and 3rd in economy sub-index.

Along with the health and safety categories, the London-based think tank used 89 variables to score each country on eight other "sub-indexes", including economy, entrepreneurship and opportunity, governance, education, health, safety and security, personal freedom and social capital. The last ones takes into account such as vague metrics wuch as marriage and religion. A lower score in "social capital" lead to the decline in the U.S. rankings.

This year the United States ranks 33rd on the Safety and Security sub-index. Safety & Security is the only sub-index in which the US ranks outside the top 30.