People often ask me about the business case for increasing women's representation at senior levels. I am glad to hear about yet more evidence as to how companies benefit from diverse management. A recent McKinsey and Company report shows that organisational performance increases sharply once a threshold of at least three women on management committees with an average membership of 10 people is reached. Significantly, where companies have an influential female presence on their executive committees, and more than two women on the board, they outperform their competitors in terms of return on equity, operating profit and stock price growth. That ought to excite corporate boards and make them realise that equal representation is more than a "feel-good"goal.