Frey and Stutzer (2002) identify certain relationships between demographic factors such as age, gender, family size, migration status, education and health, with happiness. They also identify relationships between economic factors such as income, employment and inflation and happiness. To quote:

• Age affects happiness in a U-shaped manner. Young and old people report happier than the middle-aged people. The least happy people are aged between 30 and 35.

• Women report being slightly happier than men.

• Couples with and without children are happier than singles, single parents and people living in collective households.

• Foreigners report being significantly less happy than nationals

• People with higher education indicate significantly higher well-being.

• Bad health significantly lowers self-reported happiness

Further, they say that the above relationships need not be asymmetrical and there is a possibility of selection effect (happiness determining demographic and economic status rather than the demographic and economic factors affecting happiness.