I find it hard to take seriously the concept of a happy planet. Is Earth happier than Mars? How would we know? It seems to me that only sentient beings can be happy, but that might just reflect the limited perspective of a sentient being. For all I know a rock might have a completely different perspective.

The happy planet index constructed by the New Economics Foundation (nef) doesn’t actually attempt to compare the happiness of different planets. What it attempts to do is to assess how happy our planet is with what is happening in different countries. I hope that makes you smile because if you take the happy planet index too seriously I think you are at risk of becoming unhappy – and that might make the planet unhappy!

The countries that are given the highest ratings in nef’s index are Costa Rica, Dominican Republic, Jamaica, Guatemala and Vietnam. These places don’t seem to me to offer the ideal of a good life for the people who live in them, even though many of these people say they are satisfied with their lives.

The authors claim that the results show that a good life is possible without “costing the earth”. Andrew Norton has pointed out that the results do not support this conclusion. Average happiness levels are relatively low in several countries that are ranked among the top 50 in the happy planet index.

As defined by the nef the happy planet index is a productivity measure. The numerator (or output measure) is happy life years, measured by multiplying average life satisfaction levels by average life expectancy. The denominator (or input measure) is a linear function of the average “ecological footprint”, which is a measure of the total amount of land required to provide all resource requirements plus the amount of vegetated land required to absorb CO2 emissions.

The basic idea seems to be that “the planet” becomes happier when people in a particular country become happier without using more “land” or when people maintain their current happiness level while using less “land”.

How do we know that this is what makes the planet happier? How do we know that the planet cares whether or not humans are happy?

My point is that the happiness of the planet only exists in the mind of the human who thought up the idea of the happy planet index. There is nothing wrong with trying to imagine what it would be like to be a planet that has feelings, but this is a game that anyone can play. Some people could imagine, for example, that the happiness of the planet will rise if more CO2 is produced. After all, CO2 is food for plants and planets like plants. Don’t they?

It would be possible for everyone on earth to have their own happy planet index that takes account of the things that they imagine that the planet might value. It would probably be preferable, however, to come down to earth and acknowledge that there is potential for everyone on the planet to vary in the extent to which they value various things that are important to them.

If nef’s happy planet index serves a useful purpose I think it is to remind us that surveys that measure our subjective well-being do not necessarily take into account all the things that are important to us. When we report how satisfied we are with life we take account of the things that are most salient to us at the time. We don’t necessarily take into account our own future well-being and the well-being of future generations of family members, let alone the well-being of other relatives and friends, the well-being of other humans, the well-being of animal pets, the well-being of other living things, or other matters that might be important to us.