Nick Cohen has brilliantly described how the arts and media are becoming dominated by public school products to the exclusion of people like us. This makes the irrational class-hating part of me - which is the biggest part - want to take up arms. But the rational bit of me wonders: what exactly is the problem here?

I don't think the problem is that talent is being wasted. Maybe it is, but having a few jobs done by second-rate public schoolboys rather than first-rate state school ones is surely a second-order cost. Remember that the single individual who's probably done most damage to the economy in recent years - Fred Goodwin - went to state school.

Nor even is there a huge injustice here. The financial payoffs to acting and journalism are on average small (and in journalism the non-pecuniary rewards are even smaller). Forcing bright state school people out of acting or the media and into other professions might even be doing them a favour. The biggest injustice isn't what happens to clever state school kids after 18, but rather the fact that people from poor backgrounds are much less likely to go to good universities than the rich, and that unqualified people suffer unemployment or poverty wages.

Instead, I suspect that there's another cost of having public school people dominate the media and arts. It's that this domination produces systematic ideological distortions.

For example, a Dulwich-educated stockbroker who wants to destroy workers' rights is presented in the media as a man of the people. And a man who consorts with a violent criminal and who has twice been sacked for dishonesty is spoken of as a potential Prime Minister. Such an inversion of common sense is surely facilitated by a media which regards public school backgrounds as normal and therefore unthreatening. The BBC's three most senior political reporters (Norman Smith, James Landale and Nick Robinson) were all privately educated; I suspect this imparts a bias, consciously or not.

Secondly, a media which is dominated by people from posh backgrounds is prone to over-estimate middling incomes; if you, your family and friends are on six-figure salaries, you'll regard these as more normal than they in fact are. This can lead to the interests of the well-off being wrongly conflated with those of the average person, which the result that political discourse is biased towards the interests of the rich.

Thirdly, an arts establishment dominated by the well-off is less able to portray the realities of life for the poor.

To see what I mean, picture the 1930s depression. If you're like me, your visual images come from Steinbeck and Orwell, and the aural ones from Woody Guthrie and the Carter Family. Picture the 1980s recession, and we (I?) recall the Specials, Brookside and Boys from the Blackstuff. Now picture the recent Great Recession. What do you see? What do you hear?

Nothing. Culturally, the recent recession didn't happen. And this is perhaps not unrelated to the fact that people from poor backgrounds - with the sensibilities this implies - are excluded from the arts establishment.

I'm tempted, therefore, to claim that there are costs to having the arts and media dominated by public schools.

Except that is, for one thing. Capitalism tends to produce false perceptions in people anyway; it sustains itself in part by producing an ideological bias. A public school establishment might contribute to this bias. But it would probably exist even without their efforts.