I don't like index numbers, especially the ones like this. Life expectancy is straightforward enough to measure, even though more than one measure of life expectancy exists... Average life span? Median life span? Do we include infant mortality? I think infannt mortality is a good indicator of serious unhappiness, and should be listed separately. So, even though life span is "properly quantitative", there is a lot of qualitative ambiguity in its measurement.
Then we come to ecological footprint. Clear air, clear water, food, energy, and housing are all converted to "global hectares" and added up. As if one could compensate for greenhouse gass emissions by not eating or drinking. But still, these impacts are presumably measurable, even if the aggregate is a bit dodgy.
As for life satisfaction... All we can do is ask people how satisfied they are with their life in general, or with particular aspects of it. Expressing these estimates numerically allows or even invites certain numerical manipulations that I don't think are entirely justified. And then there is the "keeping up with the Joneses" effect, where "a raising tide lifts all boats and leaves everyone feeling the same", since a lot of "life satisfaction" has to do with perceived self-ranking relative to everyone else.
Reducing everything to one number allows ranking, which is, I suspect, the whole point of many of these measures. I think it should be a rule not to take seriously any measure that is not at least two-dimensional. Nothing is 'mere'. — Richard P. Feynman
Perceptions of value are as subjective as perceptions of happiness. The difference is that there's more known about what makes people happy than there is about what makes them value things - the usual economic line apparently being based on the rigorous concept of 'Well, they just do', and some hand-waving about rational actors.
I agree that lumping in eco-footprint with other factors is nonsensical.
But let's imagine that we had an economy that took these factors into account in a less contrived way. Would it be more or less successful for the majority of the population than the one based on the metrics we use today?
The underlying issue is, really, how do the concepts we use to analyze economic activity feed back on the economic activity itself?
Something that stands out in Keynes' General Theory, by the way, is the paramount importance of subjective perceptions not only of value, but of future conditions. Nothing is 'mere'. — Richard P. Feynman
