This Wednesday sees the very first United Nations International Day of Happiness, which is being celebrated around the world on 20 March. This follows a recent resolution adopted by all members of the UN General Assembly calling for happiness to be given a greater priority. So why are people now taking happiness so seriously at national and global levels?
Happiness means the quality of life as each person experiences it. This is a key outcome in itself and is an important measure of success for any country, regardless of the level of economic development. It tells us whether people are leading lives they find satisfying and fulfilling. So information on the causes of happiness helps policy-makers to choose policy goals that serve the real needs of their people.
But, in addition, happiness is a major determinant of the other goals that policy-makers care about. Personal resilience predicts educational performance better than IQ does; and higher wellbeing improves work performance and workers' earnings. By contrast depression and anxiety account for 40% of underperformance at work, 40% of time off work and 40% of disability. Their overall cost amounts to some 10% of GDP. Greater happiness increases life expectancy; by contrast depression reduces life expectancy as much as smoking does. So happiness is a major contributor to many of our most important social goals.
As a result of 30 years of research, we now know a lot about what affects happiness. The main influences are economic, personal/social and environmental. On the economic front, income is important in every country, and poverty is a major source of unhappiness. But it is not the only thing that matters. In most countries income explains less than 2% of the overall variance in happiness (the other identifiable factors explain about 20%). Across countries, income differences explain about 6% of the differences in average happiness, while social factors explain a great deal more. Work is also vital for happiness and its importance goes well beyond the income which it provides. Education is also important, largely as a factor affecting productivity, income, employment and health.
Turning to personal/social determinants of happiness, the most important in developed countries is mental health. In these countries it accounts for 40% of all illness (weighted by severity) - more than heart disease, cancer, lung disease and diabetes all combined. It is also largely a disease of working age so that it has massive economic consequences, while physical illness is more concentrated in later life. In poorer countries by contrast physical illness has major impacts at every age but mental illness remains an equally important cause of low wellbeing.
Another crucial determinant of happiness is the quality of human relationships - above all in the family but also in the community and at work. Secure employment is vital for those who want to work and personal security against violence is vital for everyone. Good governance is essential too - wellbeing studies show the corrosive effect of corruption, and the crucial role of personal freedom and the rule of law.
Finally comes the environment. Research shows clearly the importance of today's environment for people who are alive today - including housing, urban design, transport systems, and green space. But the environment is also important in a quite different sense, since how we treat the planet today determines the world which future generations will inhabit. So when we are considering happiness and quality of life, we must take into account those future generations as well as our own.
The implications of all this evidence are far reaching. Here are six of the most important actions which are required if we want to create a happier society:
Governments should make the happiness of the people the main outcome which they pursue. As Thomas Jefferson said "The care of human life and happiness... is the only legitimate object of good government". That is why there is now a growing demand to include subjective wellbeing in the new post-2015 Sustainable Development Goals.
But, perhaps most importantly of all, we need to encourage a more empathic and caring culture, where people care less about what they can get for themselves and more about the happiness of others.
This is why I'm supporting the Day of Happiness, when Action for Happiness is encouraging people everywhere to make a personal pledge to live in a way that contributes to the happiness of others. If more of us made that our central purpose in life we would have a far happier and more cohesive world.