[simonh]

The idea that there is no middle class any more us utter tosh though, nowadays in the western world almost everyone is middle class, by any stable criteria.

Of course it depends how we define it. If the definition is some mid percentage by income then it would be fairly consistent over time because the absolute criteria would be constantly changing. However with those measures someone can maintain the same standard of living in society and leave or enter the middle class as demographics shift around them. If we use a more absolute measure that better tracks demographic change over time, such as having one third of income available for discretionary spending, or criteria such as home ownership or type of work done so we can better track changes over time, then more than half the worlds population is now middle class.