This is an important new paper using the freshest data. Abstract:
During 2006, the Gallup Organization collected World Poll data using an identical questionnaire from national samples of adults from 132 countries. This paper presents an analysis of the data on life-satisfaction (happiness) and health satisfaction and their relationships with national income, age, and life-expectancy. Average happiness is strongly related to per capita national income, with each doubling of income associated with a near one point increase in life satisfaction on a scale from 0 to 10. Unlike previous findings, the effect holds across the range of international incomes; if anything, it is slightly stronger among rich countries. Conditional on national income, recent economic growth makes people unhappier, improvements in life-expectancy make them happier, but life-expectancy itself has little effect. Age has an internationally inconsistent relationship with happiness. National income moderates the effects of aging on self-reported health, and the decline in health satisfaction and rise in disability with age are much stronger in poor countries than in rich countries. In line with earlier findings, people in much of Eastern Europe and in the countries of the former Soviet Union are particularly unhappy and particularly dissatisfied with their health, and older people in those countries are much less satisfied with their lives and their health than are younger people. HIV prevalence in Africa has little effect on Africans’ life or health satisfaction; the fraction of Kenyans who are satisfied with their personal health is the same as the fraction of Britons and higher than the fraction of Americans. The US ranks 81st out of 115 countries in the fraction of people who have confidence in their healthcare system, and has a lower score than countries such as India, Iran, Malawi, or Sierra Leone. While the strong relationship between life-satisfaction and income gives some credence to the measures, the lack of such correlations for health shows that happiness (or self-reported health) measures cannot be regarded as useful summary indicators of human welfare in international comparisons.