The SEC requires each company to disclose in its proxy statement for the annual meeting:

The growing trend among US corporations is to separate the roles of chairman of the board of directors and CEO. The traditional US model combines the chairman and CEO roles in a single individual. According to the 2012 Spencer Stuart Board Index (Nov. 2012), 43% of the S&P 500 companies separate the roles. This is up from 41% last year, 33% in 2006 and 22% in 2002.

Mid-cap and small-cap companies are more likely to separate the roles as evidenced by Equilar, Inc.'s Board Leadership among S&P 1500 Companies (Dec. 2012) reporting that 51% of the companies studied separate the roles.

Many believe separation of the roles in the US will inevitably become the norm as part of the overall move toward board independence. However, CEOs can be reluctant to share power and many companies and their boards are reluctant to accept a one-size-fits-all approach. Other companies intend to eventually split the roles but only after a CEO succession.

Both sides of the debate often agree, however, on the benefits of appointing a lead director in situations where there is a combined chairman and CEO. For those that see separate roles as the best practice, appointing an independent lead director can counterbalance many of the concerns they have with a combined chairman and CEO structure.

According to the Spencer Stuart Board Index, 92% of S&P 500 companies that combine the chairman and CEO roles have a lead director. In addition, some companies that separate the chairman and CEO roles do so with a non-independent chairman. Because of this lack of independence, these companies may opt to designate an independent lead director.

Practical Law Company has published a suite of resources which provides a comprehensive examination of the pros and cons of separating and combining the chairman and CEO roles. These resources explore statistics for different formulations of board leadership structures, proxy advisory firm recommendations and offer tips for implementing a chairman and CEO separation.

The resources also examine the lead director role, including typical powers and responsibilities and suggest considerations when structuring and filling the position. Samples of a Lead Director Charter and proxy statement disclosures for separating and combining the roles are included to aid companies and their counsel in properly disclosing and implementing the company's choice of board leadership structure.

The resources are: