London -- Costa Rica tops the "Happy Planet Index," a ranking of ecological efficiency among the world's nations, survey officials say.
Costa Ricans reported the highest life satisfaction and have an average life expectancy second only to Canada, said a release from the New Economics Foundation, a British think tank that promotes ecology and sustainable economics.
Nine of the 10 highest-scoring nations were in Latin America, with the United States reportedly "greener and happier" 20 years ago than it is today.
Of the 143 nations surveyed for the Happy Planet Index, the United States ranked 114.
