I saw the following in a recent article in the Economist magazine.

"There are some signs that Britain is already becoming a little Japanese—and not just because it is now popular to watch women in bikinis eating live cockroaches on prime-time television. For example, the trend for children to live at home with their parents has accelerated. In Japan half of those between 20 and 34 are fridge raiders; in Britain the proportion has hit one in three for men and one in six for women, with an overall increase of 6% this year alone. A supply of people able to work for less than their cost of living gives parsimonious firms a convenient pool of temporary workers. This is how two-tier labour markets, with a group of insiders enjoying job protection and a group of outsiders with none, are born. Undoing the situation can be impossible....."
(Bagehot: The stuck society-Britain has become a country where nothing much is changing (ECONOMIST Dec 8th 2012))

I have to admit that this is the first time I heard this idea: that Japan has widespread 'boomerang' adult children and that this sustains general wage-suppression which entrenches economic under-performance.
There is something intriguing about this explanation though. Are many commentators saying this?