India has scored high on the 'Happy Planet Index' that ranks nations on life indicators rather than wealth, and highlights their disparities in the levels of contentment. Costa Rica, Colombia and Vietnam were ranked among the happiest countries to live in, followed closely by India in a global measure of sustainable well-being for 151 countries around the world. Although the UK lags behind, it placed higher than other European countries like Germany, France and Spain. The US ranked way low on the Index. The three measures used to rank countries are life expectancy, environmental factors and happiness. The poll was conducted by researchers who asked people in each country how they felt, and measured environmental and health factors.