People in richer countries tend to say they are more satisfied with their lives

Putting a number on “happiness” is hard. But one way to better understand how satisfied people are with their lives is to ask them.

Self-reported life satisfaction is one key metric that researchers rely on. Respondents are asked to rate their lives on a 10-step ladder, where 0 represents the worst possible life, and 10 is the best.

The chart shows self-reported life satisfaction measured against gross domestic product (GDP) per capita. The two are positively correlated: people in richer countries tend to be more satisfied with their lives.

Of course, income is not the only thing that matters. You can also see the large spread of values for countries with similar levels of GDP per capita. For example, South American countries tend to have higher happiness levels than those in other regions.