If you want to know how well someone’s life is going, your best bet is to ask them directly. In this year’s HPI, experienced well-being is assessed using a question called the ‘Ladder of Life’ from the Gallup World Poll. This asks respondents to imagine a ladder, where 0 represents the worst possible life and 10 the best possible life, and report the step of the ladder they feel they currently stand on.
Alongside experienced well-being, the HPI includes a universally important measure of health – life expectancy. We used life expectancy data from the 2011 UNDP Human Development Report
The HPI uses the Ecological Footprint promoted by the environmental charity WWF as a measure of resource consumption. It is a per capita measure of the amount of land required to sustain a country’s consumption patterns, measured in terms of global hectares (g ha) which represent a hectare of land with average productive biocapacity.