The United Nations Human Development Index ranks the world's countries in terms of quality of life. In 2009, the Kingdom of Norway ranked first, with the Republic of Niger on the bottom. As in previous years, monarchists can take heart from what the report suggests.
Monarchies (including Andorra) unfortunately make up only 43, or less than 24%, of the 182 countries ranked. However, of the 38 top-rated countries ("Very High Human Development"), fully 19, or 50%, are monarchies; of the top 20, 12, or 60%, are monarchies. So much for republican claims that retaining a constitutional monarchy holds a country back!
The bottom 24 ("Low Human Development")? You guessed it: all republics!