Is there any limit to the audacity of Scandinavians? Not content with stirring up America's polarised politics by awarding Barack Obama a premature Nobel peace prize, they are also stirring up America's polarised debate on corporate governance.

This time the culprits are not the Norwegian politicians who award the peace prize, but the savvy investors who run Norges Bank Investment Management (NBIM), which manages a state pension fund of $400 billion (Dh1.4 trillion).

NBIM is trying to persuade four American companies — Harris Corporation, Parker Hannifin, Cardinal Health Incorporated and Clorox — to separate the jobs of chief executive and chairman of the board when they next appoint chief executives.

The fund has already scored a notable success by persuading Sara Lee to split the two jobs. It says that this is only the beginning of its campaign.

America is unusual in the power that it awards to chief executives. Splitting the two jobs is commonplace in Canada, Australia and much of continental Europe (though France is a notable exception: even Axa, one of the few French firms to separate the roles, now wants to fuse them).

In Britain 95 per cent of companies in the FTSE 350 list have an outside chairman. But in America 53 per cent of Standard & Poor's top 1,500 companies combine the two jobs.

The economic crisis has put the supporters of this bit of American exceptionalism on the defensive.

Shareholder activists are up in arms about imperial bosses, and they scored a notable hit in April when they forced Ken Lewis to surrender his second hat as chairman of Bank of America, after his decision to buy Merrill Lynch.

A growing number of bigwigs are agitating for change. Chuck Schumer, the senior senator for New York, has introduced a ‘Shareholder Bill of Rights' which, among other reforms, would force companies to separate the two jobs.

The case for separation is based on the simple principle of the separation of powers. How can boards discharge their basic duty — monitoring the boss — if the boss is chairing its meetings and setting its agenda?

Safeguards

How can a board act as a safeguard against corruption or incompetence when the possible source of that corruption and incompetence is sitting at the head of the table?

The best solution to the corporate problem is evolutionary, rather than revolutionary —pressure from activists and investors rather than sweeping legislation from Congress.

Back in 1992 Sir Adrian Cadbury ushered in a boardroom revolution in Britain when he urged companies to comply with his recommendation to split the two jobs or explain why they had not.

"Comply or explain" would not be a bad battle-cry for boardroom reformers the world over.