Non-material aspects of well-being may not be correlated with GDP per capita. For example, Social connections and connection to nature have no immediate, obvious relationship with the level of material consumption after basic needs are met. The United States exemplifies the disconnect that can occur between material consumption and well-being. It ranks in the top 10 countries in terms of GDP per capita, but it ranks 40th in life expectancy and 47th in infant mortality; it has one of the highest rates of incarceration; and more than 100 countries have a more equitable distribution of income.

There are subjective ways to measure well-being. The Gallup World Poll uses what is known as the Cantril Ladder in which people are asked to respond to the following prompt:

• Please imagine a ladder with steps numbered from zero at the bottom to ten at the top. Suppose we say that the top of the ladder represents the best possible life for you and the bottom of the ladder represents the worst possible life for you.
• If the top step is 10 and the bottom step is 0, on which step of the ladder do you feel you personally stand at the present time?

The Cantril ladder thus reduces a person’s assumptions, perceptions, aspirations, and values to a single number from 0 to 10. Country-wide surveys can produce a single score for the average person’s self-reported life satisfaction. The scale is named after Hadley Cantril, the American psychologist who developed the concept.

Self-reported life satisfaction is clearly correlated with income. Many countries in Europe (Norway, Finland, Switzerland), Oceania (Australia, New Zealand), and northern North America (Canada, United States) have high life satisfaction scores (>7). Similarly, many countries in sub-Saharan Africa have low life satisfaction scores (<4) and low incomes (Zimbabwe, South Sudan, Angola). But higher incomes do not guarantee greater life satisfaction. Czechia (6.9) and Ireland (7.0) have nearly identical levels of satisfaction, but per capita GDP in Ireland is 2.5 times higher than in Czechia.

The animation reveals some interesting trends in life satisfaction and its relationship to energy use per capita. Several countries exhibit increasing reported life satisfaction such as China (4.6 to 5.8) and Iceland (6.9 to 7.6), while others exhibit declining trends such as India (5.3 to 4.2) and Afghanistan (3.7 to 2.4). Some countries with low levels of life satisfaction such as Nigeria exhibit no trend over the period. In general, people living in countries with high levels of life satisfaction tend to use more energy per capita. Greater energy use can provide greater levels of illumination, thermal comfort, and mobility, all of which might lead a person to be more satisfied with their life.

Very low levels of energy use per person (1 to 5 GJ per person) are associated with very low reported life satisfaction (3 to 4 on the Cantril Ladder). However, relatively small increases in energy use produce big jumps in life satisfaction up to about 20 to 40 GJ per capita. This is an encouraging observation because it suggests that relatively modest upgrades in basic energy services such as clean cooking fuels and electricity service can dramatically improve the quality of life for hundreds of millions of people. Increases in energy use beyond 20 to 40 GJ per capita are associated with increases in life satisfaction but at an ever-slower rate. At very high levels of energy use, incremental increases in energy use do not produce any gains in life satisfaction. Economists call this “diminishing returns” to life satisfaction.

Countries with very high scores on the Cantril Ladder (above 7) have rates of energy use from 47 GJ/capita (Costa Rica) to 672 GJ/capita (Iceland). Clearly, a person does not have to consume energy at the rate of an American, an Australian, a Canadian, an Icelander, a person in a small, oil-rich nation in the Middle East, or a person in many affluent countries in Western Europe to be satisfied with one’s life.