The recent coverage of the investigation into allegations against the deputy president regarding corruption related to the arms deal is cause for concern.

The concern is not for the implications for the government, but rather for the role of the media.

The government of a democratic country must be accountable to the people. The question is how it is to be held accountable.

There are, broadly speaking, three institutions that are considered crucial in this: Parliament (although the ability of the legislature to exert pressure on the executive has been questioned), independent public authorities established to serve this purpose (the Public Protector, for instance) and the media.

The tendency, not only in South Africa but around the world, has been for the media to be the most powerful of these. That places a huge burden on an institution that is not formally elected by the public and whose first priority must be commercial.

There is no point in asking the rhetorical question of who watches these watchers. The only hope is to try to get the media to operate in such a way as to present information that is as balanced as possible, which the public may use to hold its representatives accountable.

The South African media may be struggling in this regard.

The popular view among journalists, and those sceptical of public representatives, is that it is better to have overly critical than overly submissive media. That is a tempting argument but it misses the fundamental point that politicians and civil servants, like the rest of us, are driven by incentives. Of the two forms that incentives can take, the carrot is at least as effective as the stick .

Undeserved criticism is likely to do as much harm as unpunished wrongdoing, not just to those under scrutiny but also to those who are supposed to benefit from their work - the public. Even worse, undeserved criticism combined with a lack of praise where warranted is likely to lead to those in public office ignoring media commentary, thereby severing the strongest link of accountability between government and its citizens.

From there, it is not such a big step to suppression of the media, and for reasons that seem perfectly rational to those in power.

Fortunately, South Africa is still far from this gloomy scenario. However, that is no reason for complacency. Which brings us to the recent coverage of Deputy President Jacob Zuma's alleged bribery in connection with the arms deal.

The print media, in particular, have not been charitable.

They have seen denials of guilt, or calls for a speedy investigation, as attempts to sweep the matter under the carpet. Such interpretations give some credence to Zuma's allegations of "trial by media" since they seem to be premised on belief in his guilt - even before he has been formally charged.

Particularly problematic, in the light of the earlier discussion of incentives, is the phrasing of the issues in such a way that the government is damned whichever way it turns.

A good example is Ranjeni Munusamy's uncharacteristically irresponsible article of last week, "There will be only one survivor", which paints the government into a corner by suggesting that either Zuma will be found guilty or Bulelani Ngcuka, the National Director of Public Prosecutions, will lose his post.

If these are truly the unavoidable outcomes, then the government either faces losing its second most senior official to scandal or being accused of interfering in the independence of an institution set up to ensure accountability. Where is the incentive to do the right thing?

Some might argue this is an isolated case, putting it down to the gravity of the allegations and their implications for South Africa. However, it is not difficult to find similar cases throughout the media on a regular basis.

Take the recent decision by the Medicines Control Council to review the legality of nevirapine. Most people familiar with the issues believe that the matter is a purely bureaucratic one that unfortunately may now have negative health consequences if not dealt with soon. Nevertheless, the media perspective has explicitly suggested that the government leaned on the MCC, despite there being no evidence to suggest this.

In a recent address I attended, a respected political analyst assessed the state of democracy in South Africa today. The focus was on electoral systems, opposition politics, freedom of expression and association. No mention was made of the role of the media, though the response of the government to media criticism was discussed.

Such an approach is both common and flawed. One cannot insist on the critical importance of free media for democracy without having some idea of what their role should be.

And those who wish to brand the government a bureaucratic donkey must be aware that using indiscriminate beatings as the only method of getting it to move forward will, in the long run, almost certainly result in it biting back.

With acknowledgements to Sean Muller and the Sunday Times.