In the first study of its kind, MBS researchers found that female director participation in UK boardrooms is around half of the previously reported total in the 2011 Davies Report.
The 2011 Davies Report for the UK states that in 2010, women made up only 12.5% of membership on corporate boards in FTSE 100 companies and this was up from 9.4% in 2004.
Yet, today's findings show the proportion of unique female directors on the boards of listed firms in the UK was only 5.1% in 2004 and 6.5% in 2010.
The research states the reasons that previous diversity studies aren't reflective is because they have only focused on the largest firms and haven't taken into account multiple directorships.
The sample used for this research was an unbalanced panel of 9,888 companies in 22 countries and over a ten-year period from 2001-2010.
This research also highlights the fact that targeting the boardroom directly with policy-dictated quotas is unlikely to be the answer to increasing the number of women on boards. It found it is more important to address the underlying causes of female underrepresentation.
The evidence suggests that for women to make it to director level, they must stay in the workforce consistently on a full-time basis ten years before they can expect to reach the board.
Tom Kirchmaier, lecturer in business, economics and strategy at Manchester Business School, said: "We must be clear as to the representation percentages we're starting from, but a better understanding of the impediments for female presence in boardrooms is crucial to be able to tackle the issue.
"Our research has found that the most pertinent criteria are that a woman works full-time and continues to even after any maternity leave.
"The ability to do this depends on the specific countries' child care arrangements and other services for families. Addressing this will have a far greater impact in the long than introducing quota policies."
