17 years after the release of the Cadbury Report, the accepted wisdom in most English-speaking countries is that, except in unusual circumstances, the same person should not hold the roles of CEO and chairman* of the board at the same time.  European countries have increasingly adopted the same practice. The USA stands notably apart, having a very high prevalence of combined CEO/chairman appointments. However, do the results justify the change?  5 years ago, professors from the Wharton Business School said that, as shown by analysis of the financial performance of US corporations, there was no evidence to support separation. Now Harvard professor Bob Pozen reports similar findings from British and European studies. Given this lack of evidence, Pozen comes out against any mandatory requirement for a separation of duties in publicly listed companies.

However, Pozen notes:

… most US firms already have an independent person performing the key functions that you would want from an independent chair. That person is the lead director, an independent board member who helps set board agendas and conveys the concerns of independent directors to the CEO. The lead director is also needed to preside over periodic executive sessions — attended only by independent directors — which are now mandated by listing standards at US stock exchanges. Choosing a lead director is a less dramatic way of fulfilling this listing standard than appointing an independent board chair.

In other words, there is a degree of separation and oversight in many USA listed companies, albeit the CEO is still the dominant player. However, notwithstanding the lack of empirical evidence one way or the other, I suspect most boards who have separated the roles of chairman and CEO, especially outside the USA, will be extremely reluctant to go back to the old model.  Boards want CEOs to perform, to get things done,  to drive the business forward, but they like the positional advantage a chairman has over a CEO on the odd occasion they need to rein the CEO in. It’s easier for a board to steer via the chair, than from the side.

Finally, Pozen adds:

… there is only one arrangement with generally negative results for a company: having a former CEO becoming the board chair of the same company. This can undermine the power of the new CEO. Unfortunately, as mentioned above, over 15 percent of US companies have this arrangement. Clearly that practice needs to change.

PS:

• I am a member of the Wellington branch committee of the Institute of Directors in New Zealand, whose recommended best practice is generally separation of duties.
• I use the chairman* title in a non-gender specific way, taking my cue from some notable female company chairmen who vehemently eschewed the “chair” title prevalent in more PC circles.