AFTER better than three decades in business, Newsnight is a broadcasting institution.

Newsnight Scotland, soon to be extinguished after 14 years, can no longer aspire to that status. The former has had its well-publicised problems, especially over the Savile scandal, but the latter is going, scrapped, finished. The possible reasons are worth exploring.

Whatever hopes are entertained for Scotland 2014 - the programme intended to compete with STV's Scotland Tonight from May onwards - the corporation has all but declared that its offering hasn't been good enough. For how long has the view existed?

Newsnight Scotland could have been relaunched; new formats and timeslots could have been attempted. A little of the money required for this new show could have been expended on the "opt-out" adjunct to the Paxman-Wark empire after years of cost-cutting. Instead, Newsnight Scotland has been put to sleep without even the courtesy of a consultation with the National Union of Journalists.

Those in charge at Pacific Quay have decided to wipe the slate clean and start again. An entirely fresh team will staff the new flagship. The versatile and experienced Sarah Smith, returning from London, will be the public face of BBC Scotland's latest effort to address the complexities of referendum politics.

Scotland 2014, by its very title, is not a programme intended for the long haul. Equally, as The Herald reported last week, no-one expects Newsnight Scotland will be reborn. For one thing, it has been losing the ratings battle with its STV rival. For another, it has repeatedly infuriated Yes campaigners in the independence argument. For a third, it has struggled with the BBC's version of identity politics.

Editorial guidelines and declarations of impartiality are poor defences for a state broadcaster faced with mass dissent from the state. The corporation is explicitly British in title and attitude. In its more romantic moments, it likes to regard itself, indeed, as a cornerstone of Britishness, the embodiment of national unity. How does an outpost cope when approaching 40% of the natives reject the very assumptions on which the BBC is founded?

Most of those 40% are licence-payers. A great many believe the corporation displays, at the very least, an institutional bias in the independence argument. BBC Scotland is well aware of the complaints. Recently, however, it has also had to confront detailed research by Dr John Robertson and a team at the University of the West of Scotland showing that the first year of referendum coverage (to September 2013) "has not been fair or balanced".

The findings are directed at both BBC Scotland and ITV, but the corporation has borne the brunt. It has also defended itself with passion, attempting to find fault with methodology, terminology, "factual accuracy" and definitions - what does Robertson mean by "fairness"? Rather than simply invoke its guidelines, the corporation has chosen to contest almost every aspect of research based on 730 hours of viewing - of the BBC and ITV - over a year.

Wounded professional pride and a desire to protect the corporation's reputation are no doubt at stake. But BBC Scotland has shown itself to be sensitive indeed to charges of bias, especially when they come with numbers and dates attached. How are stories couched? In which order are questions posed? To what extent, even unconsciously, do BBC personnel side with the status quo?

Robertson's findings are stated in cautious language. As a researcher, he has obligations. So for that matter does the BBC. A newspaper columnist, in contrast, has no such inhibitions. Though some politicians would have it otherwise, newspapers are free to adopt positions and endorse opinions. Broadcasters, the BBC above all, have no such liberty.

It's a tricky area. How much leeway do you accord an interviewer such as Jeremy Paxman or Gordon Brewer? One fascinating moment in a recent exchange of letters between Robertson and Ian Small, BBC Scotland's head of public policy and corporate affairs, comes when the word "impartiality" is invoked. The researcher, a reader in media politics, rejects it out of hand: "Impartiality is not attainable." He prefers fairness and "self-awareness".

I happen to agree with that. True impartiality, like complete objectivity, is not available to a human being. You can only try to be fair. That fact presents a problem to anyone who denounces bias when all they really mean is "a statement with which I disagree". But equally, a BBC wedded to its cherished reputation for "impartiality" has a very big problem if a large part of its audience believes it is being unfair.

Put aside the truth of the matter for a second. BBC Scotland is confronting the perceptions of a large minority among its listeners and viewers. The charge of bias among Yes campaigners is now commonplace. The BBC can say, rightly, that it was ever thus; that it is assailed routinely by political parties seeking to exert pressure.

The people at Pacific Quay can tell you, indeed, that the biggest controversy over bias it has faced hitherto came in August 2012 when Labour's Ian Davidson, MP for Glasgow South West, accused Newsnight Scotland and the presenter Isabel Fraser of favouring the SNP. The programme was "News-Nat Scotland", said the ever-witty MP. During the broadcast, Fraser asked the MP to apologise for his "offensive" claim. Davidson didn't.

I say, because I can, that Davidson picked a fight. But I also say the British Broadcasting Corporation too often treats the campaign for independence as a claim to be refuted. That conclusion is based on nothing more than the less-than-intensive research of a licence-payer and a knowledge of how the Better Together parties would react if the BBC behaved in any other way. But such is my "perception".

For what it's worth, the view has nothing to do with daft arguments over Sarah Smith or Jim Naughtie being "parachuted in" to provide part of the BBC's referendum coverage. The phrase "Anglo-Scot" is insulting to all expatriates. Scots have been finding work and making careers beyond the Border for long enough. Whether their return is a judgment on Scottish-based talent or a version of the old cringe is for viewers to decide, as they will. These matters are irrelevant to institutional bias.

Against that, opinions are hardening. How difficult is it to be fair in an argument between Yes and No? The sudden culling of Newsnight Scotland says the BBC knows it has failed to give a satisfactory answer.