FOR all the scrutiny journalists heap upon others, it is remarkable how little attention we pay to our own craft. But it is difficult, and downright awkward, to criticise one's colleagues. And the whipper-snapper down the hall who cannot string two sentences together may be your boss one day. So the most forthright criticism of the press is often performed by outsiders.

One of those external critics is Barack Obama. Unsurprisingly, the New York Timesreports that the president is frustrated by the fourth estate. But Mr Obama has a point. According to the Times, he has complained about the press's focus on political point-scoring and, more interestingly, of “false balance”, or how reporters give equal weight to both sides of an argument even when one side is factually incorrect.

Many assume that balance is a key element of good journalism. Fresh-faced journalism students often arrive with the dewy-eyed aims of pursuing the truth and preserving balance and objectivity. Objectivity is easy to dismiss. It just doesn’t exist. There, I’ve said it. But balance is a trickier beast. Balance can be a great asset in an article. It can also be ruinous.

The problem of balance is neatly explained by a British hack, Nick Davies, who wrote a seminal (and underrated) book on falsehood, distortion and propaganda in journalism called "Flat Earth News". Mr Davies does a bit of teaching, and he has his students imagine that they are asked to write a report on what the weather will be like tomorrow. They interview a woman in one room who says it will be sunny. Then they interview a man in another room who says it's going to rain. Your job, as a journalist, is not to simply write up what you have been told, he says. Your job is to look out the window.

Writing a "balanced" version of this story would produce an article that reads “he says it will rain” but “she says it won’t”. You have all these quotes fluttering around like “butterflies in a jar”, going nowhere. But there is a bigger danger lurking. What if the man who says it is going to rain is lying? What if he is an umbrella salesman? Your options are to either make a judgment about the truth, or print what you have been told. But if you balance an article when you know that all the evidence points to a sunny day tomorrow, then you are participating in a denial of truth.

It should be obvious that this made-up scenario has parallels in climate-change reporting, an area of journalism that has been dogged by the issue of balance. When climate-change sceptics felt that reporters were writing about the issue as if it were accepted fact, they pushed hard to create a sufficiently large body of “experts” and “evidence” in order to force journalists to take cover under the trusty shield of balance. A controversy was created, where none had existed, by those who stood to gain. And thus journalists felt obliged to give equal weight to both sides of the debate.

Today, creating uncertainty in order to hijack the concept of balance is a significant industry. Public-relations firms create artificial "grass roots" organisations for business and political-interest groups in order to have their views reflected in the media. They are known as “astroturf” groups, a concept that might not even exist if not for the demand for so much balance. For a recent example, see this brilliant series in the Chicago Tribune describing how the chemical industry created a phony consumer watchdog group to successfully push for the greater use of flame retardants. (Some have even suggested that the tea party is an astroturf movement.)

Why are journalists susceptible to these tactics? Jay Carney, the White House press secretary, suggests that political journalists aim to look high-minded by making both sides look bad. I think the motivations are far more trivial. Balance is easy and cheap. In political journalism, a vitriolic quote from each side and a punchy headline is all that is needed to feed the news machine. Who cares if substance and analysis are thrown to the wind? Journalism is a commodity. There is always a need for more “inventory” on which to place ads. Journalism, real journalism—the pursuit of truth—also creates inventory, but not as much, and it is difficult, costly and time-consuming. Far easier to bolt together a few pieces of trivial comment from political pundits and move on.

Ironically, the Times falls into the balance trap in its very own article. After suggesting that false balance is some lefty concept rather than common sense, the Gray Lady feels compelled to interview the editor of the “left-leaning” Talking Points Memo as well as the creator of the "conservative" Power Line. The latter cannot resist giving Mr Obama a poke in the eye, but both quotes are so devoid of meaningful information about the concept of false balance as to be farcical.

Let me end, though, with a word in favour of balance. There are many issues that demand such an approach. We don’t always know the truth, and some questions are hard to answer definitively. Research is constantly providing us with new theories. Do charter schools work to improve student achievement? How effective is foreign aid? What is the best way to bring down health-care costs? These are topics that deserve a balanced approach, but one that deals in substance, not traded insults. So when is a balanced approach correct? That, I’m afraid, is a question of judgment.