There is a lot of talk about bubbles, and how we need to do something to prevent them.  I find this difficult, as even if we could observe bubbles we also really need to justify why we should lean against them – as long as the cost falls on those getting themselves involved in the bubble I’m not sure what the issue is.

However, if we are going to do things I think I’ve identified a pretty obvious bubble:

The use of the word “sustainable“.