Having more women in decision-making roles may boost companies' performance on the stock market, according to Credit Suisse.
In its "Gender 3000" report, published Thursday, the Credit Suisse Research Institute (CSRI) found a link between firms with more female leaders and stronger share price performance over time.
Researchers analyzed a slew of data from 3,000 companies across 56 countries between 2012 and August this year. The resulting report was the latest installation in a long-term analysis of gender diversity and corporate performance, with the previous report published in 2016.
Although analysts "fell short of definitely asserting cause and effect," they found strong correlations between diverse management teams and share price outperformance.
Shares of companies with more than 20% female management had outperformed those with less than 15% female management by 5% so far this year, the report said.
The data showed that this was a long-term trend. Shares of firms that had more women in management outperformed those with male-dominant management almost every year since 2010. Credit Suisse also found that industries with greater levels of gender diversity in management had higher levels of profitability.
The Philippines, Thailand and Australia had the highest proportion of women in management, while Japan, South Korea and India had the least.
Meanwhile, the financial, health care and utilities sectors were the industries with the most female managers, according to Credit Suisse.
Italy, Singapore and Thailand had the most female CEOs, while Germany, Japan, Malaysia, Spain and Turkey had no women in chief executive positions when Credit Suisse looked at samples of at least 20 companies in each country.
Having women in boardrooms also boosted returns for shareholders, according to the report.
Its authors said cash flow returns on investment were found to be 2% higher over time for companies with a higher proportion of female senior managers, with shares of more diverse firms also exhibiting less volatility.
France, Norway and Belgium had the highest proportion of companies with women on boards.
In terms of sectors globally, communications, consumer discretionary and consumer staples sectors had the most gender diverse boardrooms.
Overall, Europe was the region with the most diverse corporate boardrooms, followed by North America.
Although Credit Suisse noted it "appears to be the case" that gender diversity helps to boost corporate performance, the report stressed it was not the only factor that can lead to better share price and earnings. No variables other than gender diversity were measured against corporate performance in the analysis.
A strong share price was a reflection of a good business model, the report's authors added, which could be both the consequence and the root of gender diversity.
"How, and if, diversity contributes to the strategic decision-making that delivers superior and stable returns is the key rather than diversity per se," the report's authors noted. "Other factors can always be at work. In fact a conundrum remains here as to whether greater diversity leads to a higher quality business model or whether a high quality business model leads to greater diversity."
Previous studies have suggested that companies with a greater gender balance achieve stronger corporate results.
Last year, a report from MSCI showed that having women on boards increased corporate productivity. And according to management consultancy McKinsey, companies with the most gender diverse executive teams are 21% more likely to outperform on profitability.
Research from the International Monetary Fund (IMF) has also linked productivity to gender diversity. In a blog post in November, Christine Lagarde, the organization's former managing director, and Jonathan D. Ostry, deputy director of the IMF's Research Department, said women and men "complement each other in the production process."
"In other words, adding more women to the labor force should bring larger economic gains than an equal increase in male workers," they said.
Meanwhile, in a survey of 21,980 firms from 91 countries last year, The Peterson Institute for International Economics found that employing women at C-Suite level significantly increased net margins.
However, according to one academic, a diverse workforce alone is not enough to stimulate productivity increases. In an article published by the Harvard Business Review in March, Letian Zhang of Harvard Business School said his research showed gender diversity related to more productive companies — measured by market value and revenue — but only in firms where there was a widespread cultural belief that gender diversity was important.
Commenting on Credit Suisse's findings, a spokesperson for the U.K.'s Fawcett Society — an organization advocating gender diversity in the workplace — said firms with greater female representation were more successful than their less diverse counterparts.
"(This) report also shows that women continue to be very under-represented at the top of these U.K. companies," they said. "As the findings show, companies that are more diverse deliver better results."
Areije Al Shakar, director of Bahraini venture capital firm Al Waha Fund of Funds, added that there was a growing body of research indicating the importance of diversity for business, and crucially, profitability.
"We're seeing VCs around the world starting to take note," she told CNBC via email. "Today's growing focus on factors like diversity, which are being taken into account like never before, also has strong implications for the Middle East — a surprising global leader in startup diversity, with one in three startups founded by women."