But it's bad for the returning kids too. True, you don't have to pay much — or any — rent. Your clothes are ironed, your meals cooked. But jokes aside, you're excluded from parts of the labour market which you want to thrive in. Think-tanks and big banks, advertising and consultancy, politics and publishing — these professions are located in the cities. Those who don't live close, or can't afford to, won't access internships and low-paid jobs needed to enter these careers. 

Ambitious young people will be left frustrated, seeing their university peers from more affluent backgrounds excel only because parents' money was there to support them through the initial period of poverty wages. Half of all young people now feel they will not achieve their goals. Research by the Prince's Trust reveals that one-quarter of all 16-25 year olds are regularly down or depressed. And depression does not help self-motivation, the very trait needed to seek out job opportunities.

But UK competitiveness will suffer too. Businesses will have a smaller supply of graduates to select from. Boomeranging is a social trend that should give all of us — and not just my brother — serious cause for concern.