According to that invaluable website, Quote Investigator, there's considerable doubt that John Maynard Keynes ever said "when the facts change, I change my mind. What do you do, sir?"

The nearest QI's investigators could come to that famous line was an attribution to Keynes by fellow economist, Paul Samuelson: "When my information changes," he remembered that Keynes had said, "I change my mind. What do you do?"

And that is rather the situation in which I find myself. I've been absent from The Drum for a couple of weeks, but the last column I wrote toed the standard media line on the idea that more regulation of the media - especially the print media - could possibly be a good idea.

What surely we don't need - not at least until it's forced on us by conduct which so far as we know has not and is not occurring in Australia - is a state-appointed regulator to enforce good behaviour on the press.

Since then, a few bits of information have come my way that have led me, if not to a fundamental change of mind, at least to an appreciation of the frustration that the press's complacency and self-importance can engender in non-media folk.

One of those bits of information is still on its way for most readers. I've just read a preview of an 8,000-word profile of Chris Mitchell, the editor-in-chief of The Australian. It will be publicly available in The Monthly on Friday. Its author, Sally Neighbour, is a former colleague of mine, who worked for many years at 4 Corners, but more recently has written mostly for The Australian. Her profile is certainly not an encomium, but nor is it a one-sided attack. Mitchell has many admirers, inside News Ltd and out (two of them are Rupert and Lachlan Murdoch, which will not have done his career any harm); and she makes that clear.

Nevertheless the picture she paints, like the newspaper Mitchell edits, is sometimes disturbing. Some brief extracts:

According to a News Limited insider, "Mitchell has inculcated a view [at the newspaper] that they are there not only to critique and oversee the Government, [but also that] it is their role to dictate policy shifts, that they are the true Opposition." "He's an editor who likes to be involved and mix it with the power players," says (Walkley-award winning Queensland reporter) Tony Koch. … Another close associate says it's not about party politics for Mitchell: "It's about power." Some reporters complain of constant interference: "An editor will come and say 'Chris wants this' and it's understood that, no matter how crazy or unreasonable it is, it has to be done," says one. Mitchell's aversion to criticism stops many people from speaking out. Of the 70 people I spoke to for this profile, two-thirds would talk only off the record. "You can't be quoted in relation to Chris Mitchell. He's so vindictive," said one. Chris Mitchell once told a colleague, "You have to understand - this is a dictatorship and I am the dictator."

No-one who's a regular reader of The Australian, especially if they've been on the receiving end of one of its vendettas, would have any trouble believing those descriptions. But let's admit that to a greater or lesser extent they could describe many other successful and charismatic newspaper editors over the past hundred years.

But it's a picture of almost untrammelled power (well, trammelled only, in Mitchell's case, by the whim of Rupert Murdoch: if Mitchell ever lost Murdoch's support, nothing else could save him; so long as he has it, nothing else can touch him).

And yet untrammelled power, in others, is just what The Australian is determined to check. In the wake of an attack on News Ltd papers by Communications Minister Stephen Conroy, The Australian (Mitchell himself? - one suspects so) penned one of its self-congratulatory editorials:

While the Fairfax press and public broadcasters seem inured to wasteful spending of taxpayers' money, we have adopted a more traditional approach to journalism - providing scrutiny of government to ensure the public is well served. …newspapers like ours are fulfilling their public duty by holding politicians to account...

A few days later, Sydney's Daily Telegraph - a newspaper now under the editorship of Paul Whittaker, fresh from The Australian, where he worked directly under Chris Mitchell - chimed in to defend its coverage of the carbon tax debate:

In truth, The Daily Telegraph is simply doing what it has always done, and done well - holding the government of the day to account…. Major nation-changing initiatives require this level of examination. Without it, readers would be left uninformed and political debate in this country would be debased.

Well, many think that debased is exactly what political debate in this country has become, thanks not just to the politicians on both sides (though they should certainly take a share of the blame) but to the way it is being covered in the media - and especially in News Ltd newspapers.

The Australian's editorial contained this statement:

The public appreciates facts, is thirsty for them, and is always capable of making up its own mind.

Well, yes, the public does appreciate facts. But what it gets from newspapers, more and more, are opinions. Opinions in the opinion columns. Opinions in the 'analyses' that are scattered through the news pages. And opinions, in the form of emotive language, selective fact-picking, and one-sided argument, in the news stories themselves.

On Media Watch, we highlighted a couple of examples from The Daily Telegraph a couple of weeks ago. And this Monday, a classic on The Australian's front page.

At this stage, some of my readers will be sharpening their keyboard quills to pen furious comments, to be appended below, about the sheer hypocrisy of an ABC journalist talking about bias or opinionated news. Look at this, and that, and the other. Outrageous leftism! Slavish copying of The Australian's right-wing agenda!

But here's another bit of information that came our way since my last column was published. Essential Media (an outfit that admittedly does most of its work for clients on the left of the spectrum, like the ACTU, but whose basic sampling methods are, so far as I know, respectable) published the results of a poll about attitudes to the media.

It showed that trust in the news and opinions to be found in Australian newspapers has taken quite a dive in the past year. In March 2010, 62 per cent of the sample had some or a lot of trust. In July this year that figure had slumped to 53 per cent. (The Daily Telegraph, with only 45 per cent expressing any trust, did notably worse than The Australian, The Age and The Sydney Morning Herald).

A similar decline was evident for commercial TV news and current affairs. There was even less trust in commercial radio news, and less still for talkback radio, news websites and internet blogs.

During the same period, trust in the news and opinions of one news outlet increased: the ABC's. Seventy-one per cent of the sample said they had some or a lot of trust in ABC Television news and current affairs, up from 70 per cent the year before. Trust in ABC radio news and current affairs was a bit lower, but still up there at 67 per cent.

I don't record this to crow. It was a small sample. Perhaps it wasn't a true cross-section of the population - I haven't conducted any research into Essential Media's methods. But it does lead me to make this observation:

Of all media outlets in Australia, the ABC is by far the most heavily regulated - especially, though not exclusively, by itself. Believe it or not, ABC journalists and editors are well aware that it's 'your ABC': that the taxpayer pays our wages, that that funding is forthcoming on certain conditions, and that the conditions need to be taken seriously. Foremost among them, for journalists, is a requirement for accuracy and fairness.

The ABC's Editorial Policies are published. Complaints are taken seriously. Certainly, most are rejected, but some are not, and ABC staff know that being at the wrong end of an upheld complaint is not good for their careers. And no editor, not even the director of news, can change the decision of the complaints-handlers at Audience and Consumer Affairs, which sits outside the News chain of command.

But who, to use their own phrase, holds newspapers to account? In particular, who can hold an editor like Mitchell or Whittaker to account? The Australian Press Council can uphold a complaint, but no-one within News Ltd would take that as a black mark against an editor who otherwise retained the favour of Messrs Hartigan and Murdoch. So long as they retain that favour, they are free to do pretty much as they please; and the evidence is that quite often they please to follow a news agenda which doesn't just hold elected politicians to account, but, in the elegant phrase of a pollie quoted by Sally Neighbour, 'reports politics in any way that shits on the government, day after day'.

I'm still not convinced that regulating newspapers in the way that the ABC, or even commercial TV and radio, are regulated is possible or desirable. But it seems to me that newspaper editors would do well to think about what those poll figures are telling them.

To quote once more from The Australian's editorial: On these matters, neither the rantings of ministers nor our ripostes will be the last word. Rather, through the news stands and the ballot box, the people will decide.

Well, if the news stands were the last word, The Australian would never have got off the ground, or been sustained during the decades that it made a loss. Even today, its readership, and its profits, are both far smaller than its influence. It is sustained through the will, not of its readers, nor the public as a whole, but of one man.

And the idea that sales figures alone can 'hold to account' newspapers like The Daily Telegraph, The Herald Sun, The Courier Mail and The Advertiser - papers which dominate their markets, and in some cases are effective monopolies - is, when you think about it, absurd.

Great newspapers, and their editors, wield both power and influence. If they don't wish that power to be regulated by others, they should take much more convincing steps to hold themselves to a set of standards that are published, and transparently enforced.

Rupert Murdoch explained his decision to close down The News of the World like this: "We felt ashamed at what happened. We had broken our trust with our readers."

Well, there's no evidence of phone-hacking in Australia. Nevertheless, the evidence is that the trust of newspaper readers here too is eroding. That's something that should surely concern even the most powerful editors.

Jonathan Holmes is the presenter of ABC TV's Media Watch.