The South Korean study that I'm aware of is described at http://hbswk.hbs.edu/item/6498.html and found that a 10% increase in women managers was associated with a 1% return on assets. There is every reason to believe that this effect is stronger in South Korea than in the USA, and there is no way to get near the quoted 33% more with that measured effect.
Try this one then - an in-depth, fact-based, study by McKinsey & Company: http://www.mckinsey.com/locations/swiss/news_publications/pd...
"Statistically significant studies show that companies with a higher proportion of women on their management committees are also the companies that have the best performance."
Interesting. The key things that stand out to me from that are the following:
1. They are analyzing the impact of having women in top management. The Korean study looked at women in middle management, where they presumably have less of an impact on overall corporate direction.
2. The Korean study was looking at companies in a single relatively uniform economy. The McKinsey data set looks at companies across a variety of different countries with different economies and cultures. There are very strong correlations between which country a company is in, and whether it had women in the boardroom.
3. The McKinsey study identified a number of specific reasonable reasons why awareness of a female perspective could be beneficial for companies. If you're in a consumer line of business, those reasons are worth paying attention to.
Do you know whether McKinsey tried to crunch the numbers to estimate how much of the difference in economic performance can reasonably be attributed to having women in the board room versus the company being in a country whose economy did well? (Yes, I'm aware that there might well be a correlation between gender equality and the country's economic performance. Getting conclusions out of real world data sets will always be ugly and messy.)
The South Korean study that I'm aware of is described at http://hbswk.hbs.edu/item/6498.html and found that a 10% increase in women managers was associated with a 1% return on assets. There is every reason to believe that this effect is stronger in South Korea than in the USA, and there is no way to get near the quoted 33% more with that measured effect.