According to the recently-released 2016 Board Practices Report, a collaborative board practices benchmarking effort between Deloitte LLP's Center for Board Effectiveness and the Society, the most frequently-cited (15%) average tenure of all non-management members of respondents' boards is 9 years, although 6 years is a close second - cited by 13% of respondents.
Looking at sector-specific variations, 6 years average tenure was the most frequently-cited (14%) among Non-Financial Services companies. Large- and Mid-Caps fall in line with the overall findings of 9 years and 6 years, ranking first and second-most common, respectively, whereas Small-Caps are in their own league - with >13 years being the most frequently-cited (22%) average board tenure.
As previously reported in the Society Alert, in February, leading asset manager and global investor Legal & General Investment Management re-issued its guidance on board refreshment (initially published last year, which we then reported on here and here) - which will inform its engagement and proxy voting decision-making for US portfolio companies beginning as of this year - indicating that it will vote against Nominating Committee Chairs if the average tenure of the board is 15 years or longer or if there have not been any new board appointments for at least 5 years, and will vote against key committee members and/or the lead independent director if they have been serving for 15 years or longer. And other investors (see, e.g., this Dorsey memo) have also adopted director tenure proxy voting guidelines to prompt board refreshment and/or based on independence concerns.
The iconic Board Practices Report - which presents findings from a survey distributed to the Society's public company members in late 2016 - covers trends in over 15 areas of board practices and hot topics including cyber risk, shareholder activism, and board diversity.