beyond a single currency

The World Bank's new clean energy czar Daniel Kammen tells the New York Times that one big hurdle is getting economists to recognise the value of externalities.

Our economy is fixated on one metric, money ... we need to put a value on the quality of our energy systems, the ability to preserve nature, to preserve the oceans and the rivers.

I sort of liken this to the invention of money. We now need to [move] beyond our single currency value to one where the social and environmental parts of the story are equally represented. That’s the next challenge.