Maybe my readers can help me out here. I’m researching the link between gender diversity and company performance, and having read about 20 academic papers on the subject I’m now looking at studies various companies have done. Currently I’m on this one (.pdf) from Credit Suisse, in which they evaluate 3,400 companies across 10 sectors in 40 countries including 27,000 CEOs and senior executives. This graph on page 25 is confusing me:
If you were to plot the share prices of two random companies, you’d not expect them to follow the same path. If you were to plot the share prices of two companies in the same industrial sector exposed to much the same market forces, you’d perhaps expect to see them follow similar paths. But how likely is it that you take 3,400 companies across 10 sectors and 40 countries, divide them into baskets depending on the number of women in senior management, plot the share prices and they all have roughly the same shape?
Given the only differentiation between the baskets is the number of women in senior management, I’d have expected each line to be of a different shape, reflecting the combined fortunes of each individual company in each sector in each country. Is this a complete fudge, or am I missing something here?