Biggest gaps in prize money
Similar pay gaps can be observed across other professional sports. In golf, men in the US Open compete for a chance to take home almost $1.5m (£1.1m), twice as much the prize money for the female champion.
Take the case of Lydia Ko, from New Zealand, who in 2015 became the youngest player of either gender ever to be ranked number one in professional golf.
That year, she pocketed less money than the golfer in position 25th in the male ranking of the PGA Tour, estimates by Newsweek reveal.
Meanwhile, in cricket a victorious male team at the World Cup can make almost seven times more than the women's side.
And the pay gap is replicated also in the world's most prestigious male and female basketball leagues - the NBA and WNBA.
"The highest-paid player in the WNBA (the Women's National Basketball Association) makes roughly one-fifth that of the lowest-paid player," in the super-rich NBA, calculates Newsweek.

'A boys' club'
To achieve equality, experts say, it is not enough that the governing bodies of each sport establish gender-blind prizes - sponsorship and endorsements, as well as contractual conditions, have become some of the main forces perpetuating the imbalance.
In tennis, for instance, the Grand Slams - the four most important events in the global calendar- have already introduced equal pay for men and women from 2007, yet the top male players consistently earn more yearly due to better sponsorship deals.
That is why Serena Williams is alone in the Forbes' list of the 100 richest.
"The top 100 athletes are a boys' club more than ever", wrote Forbes' sports reporter Kurt Badenhausen when the list was released, in June.
"Mainstay Maria Sharapova failed to make the grade after reductions in her endorsement contracts." 
Those extras make up 29% of the total pie for the top 100 athletes, according to Forbes.
Ronaldo earned $58m (£44m) in salary and bonuses, but topped that up with some $35m (£26.5m) from sponsors, endorsements and appearance fees.
For golfer Tigers Woods and track star Usain Bolt, sponsorship account for over 90% of their earnings.
"Sexism is widespread from grassroots level to elite level in the sport industry," says Frey.
"At grassroots level it may mean that girls are not able to participate in a sport that is not traditionally considered to be for girls, creating bias at an early age which then follows them through youth and on to elite sport practice."
Then, she says, it translates into uneven opportunities in sponsorships and personal marketing, to the extent that most female athletes around the world are "unable to secure a livelihood from their athletic practice". 
And the trend persists after retirement.
"For retired sportswomen it is particularly problematic. Not only have they not ever earned very much money, they've probably got no pension, no house, no security," says Hathorn.
"And that's an issue for girls' aspirations: why would they want to become athletes if that's what the future holds?"

Understanding the gap
The roots of this discrepancy could perhaps be traced back to the origins of modern sport itself.
Different societies viewed physical training as an activity intrinsically linked to the "muscular male", defined against an idea of softer and more physically vulnerable femininity. 
The father of the modern Olympic Games, Pierre de Coubertin, described women's sport as an "unaesthetic sight" for the human eye and considered their participation would make the competition "impractical, uninteresting" and "improper" (although a few female athletes were allowed to take part after 1900).
Women were only competing in races up to 1,500 metres, because they were deemed physically unprepared to cope with the demands of longer events.
In terms of representation, it took until the 2012 London Games to have at least one female athlete in every country's delegation.
So the sport pay gap may well be linked to a wider imbalance - that of female participation in sport, perpetually lower than that of males.
"The participation is a problem that goes back to the school years: that's when it starts," says Ruth Holdaway, chief executive officer at advocacy group Women in Sport. 
It has to do with their awareness of the body, with how they are perceived and the gender stereotypes they encounter, says Holdaway.
UN Women statistics show that a striking 49% of girls drop out of sport by the time they reach puberty, and this has ramifications in professional and elite training later in life, research shows.

Turn on the TV
There is a general acceptance that the breadth of the gender pay gap is also a by-product of the increasingly commercial nature of sport, where media rights play a big part.
According to a study by the University of Minnesota's Tucker Centre for Research on Girls and Women in Sport in 2014, only up to 4% of sports media coverage went to female sports, despite the fact that 40% of all participants were female. 
And within the small amount of airtime received, the coverage of women's athletics is also more likely to be sexualised, portraying athletes off court and out of uniform, with an emphasis "on their physical attractiveness rather than their athletic competence", says Tucker Centre's director Mary Jo Kane.
Hence, many would argue that women earn less because the market dictates so, as female sports are "less popular" and "not as good to watch", and as a result they generate less media revenue. 
It is a self-perpetuating, "chicken and egg" cycle, equity advocators argue - audiences will not get excited about women's sport as it gets minimal exposure in the media, and the media would justify the lack of coverage by saying that female athletics do not generate enough audience engagement.
"That is not a fair argument, you have to invest first at many levels, including marketing and promotion, to get the general public more involved, and then the return of the investment will be better," says Frey.
"Had our culture been used to seeing women rather than men playing rugby or football for generations, we would find the idea of men playing sports rather novel," adds Hathorn. 
Sport gaps are in fact a manifestation of wider gender inequality, says the expert, that also translates into other more subtle forms of sexism.
For example, women footballers in international tournaments were required until recently to play on artificial turf, which is often regarded as of lesser quality than the natural grass on which male teams play.
And then there's the language: "the World Cup is assumed to be for men, while women require the qualifying 'Women's' to describe their event", says a UN document on women in sport. 

Good record
Despite the "glacial" pace, change is nonetheless advancing and indicates that the gap is getting narrower.
Tennis is usually celebrated as a shining example of this, after all four Grand Slam tournaments established equal prize money to the men and the women in 2007.

Sports paying equal prize money (number of sports per year)
In fact, the process started in 1973 at the US Open, thanks to world champion Billie Jean King and other female players, who founded the Women's Tennis Association to fight for gender equality.
Athletics have also become a case study for good practices, particularly over the past five years, with the International Amateur Athletic Federation (IAAF) World Championships and annual Diamond series offering gender-blind rewards.
Other sports that have reportedly been paying equivalent prizes include skating, shooting, volleyball, diving, sailing, windsurfing and taekwondo, as well as some cycling events.

MPW Insider is an online community where the biggest names in business and beyond answer timely career and leadership questions. Today’s answer for: What do you think is the most significant barrier to female leadership? is written by Beth Brooke-Marciniak, global vice chair of public policy at EY.

According to research by Michigan State University’s Institute for the Study of Youth Sports, approximately 70% of children in the U.S. are dropping out of organized sports before the age of 13. This is particularly alarming for women because studies have shown that girls who play sports are more likely to graduate from college, find a job, and be employed in male-dominated industries.

EY research shows that among senior business women in the C-suite today, 94% played sports and over half played at a university level — suggesting a strong correlation between their success in sports and their success in business. In fact, of the 400 women EY surveyed, 75% said that a candidate’s background in sports positively influenced their decision to hire them. These women put a particular premium on female athletes because they know — very personally — how participating in sports can impact work ethic. So to have young women drop out of sport at an early age is not only an alarming statistic, it is a wake-up call for parents. Their girls could prematurely be walking away from something that could have a bigger long-term effect.


These statistics have caused me to reflect on my own experience as a young athlete, and specifically the role my parents played. I was a four-sport athlete in high school. I played basketball, softball, tennis, and golf. My true passion was softball, but basketball was an intercollegiate sport. I eventually decided to pursue basketball in college at Purdue and leave the other three sports behind. But my parents never tried to make me pursue just one sport. I loved the variety. I only narrowed to one sport in college when, as a scholarship athlete, it was necessary.

My father empowered me to play. He and my mother showed up to every game. They truly cared. And I loved having them there. I can’t imagine a world where they weren’t there. But there was never an expectation. They just loved watching me play. And I loved them watching me. Often, my father and I would discuss my performance after games, but only if I wanted to. I would ask him questions, and he would answer. We discussed ways I could improve, and he would practice with me in our backyard. He knew I didn’t need to be told I had made a mistake, but rather understand how not to do it again. And he would help me with that.

There’s no doubt that it was my parents’ interest and support that encouraged me to continue playing sports throughout my childhood. Their interest was pure joy, not judgment or unfair criticism. They were all in because I was all in. When I was younger, organized sports was still novel for girls. When my friends quit playing, and dropped out to be “more like girls,” I kept going. And my parents went with me. I never wanted to stop, so I didn’t. And I know that the nonjudgmental, joyous support of my parents was a huge factor — not only in my success as an athlete, but also in my professional success today.


I’m not alone in accrediting my career success back to my experience as an athlete. Later this week, I’ll be taking part in a discussion at the NFL Women’s Summit with Claire Shipman, television journalist and co-author of The Confidence Code. Claire and I will be among women leaders from business, government, sports and a variety of other fields taking part in what promises to be an amazing exchange of ideas.
In Claire’s words:
“Something happens when girls play sports — they embody the experience of not just of winning, but the critical experience of losing. It’s that process of carrying on and clearing hurdles that really builds confidence. It’s an incredibly useful proving ground for business and leadership.”
That “something” happened to me when I played the sports I chose. And it was the constant support I received from my parents that made possible the success I’ve experienced. Our EY research is further proof that there is a strong connection between sports and women’s leadership at the highest levels. So I encourage all parents to think hard about encouraging your daughters to stick with sports — your decision could affect the rest of their lives.

Three efforts could kick-start progress to get more women in leadership positions.
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The case for gender diversity is compelling, but McKinsey research—including a new report, Women Matter 2016: Reinventing the workplace to unlock the potential of gender diversity—shows many companies are struggling to ensure women are represented fairly in top management. Progress toward parity remains slow. In Western Europe, only 17 percent of executive-committee members are women, and women comprise just 32 percent of members of corporate boards for companies listed in Western Europe’s major market indexes (exhibit). In the United States, the figures are 17 percent for executive committees and just under 19 percent for boards.

Would you like to learn more about our Organization Practice?

European women work more part-time and more unpaid hours than men. Our new study found a correlation between the representation of women in leadership positions and women’s employment rate, as well as their hours of unpaid work. Increasing the number of women in top management requires tackling these two inequalities. Governments have a strong role to play in addressing this issue and creating the conditions for equal opportunities. But companies also have to do their part.

​To better understand what companies do, and what they could do further, in 2016, we surveyed 233 companies and 2,200 employees in nine European countries.1 Analysis showed that while the vast majority of companies have introduced measures to increase gender diversity at the top, many have yet to see significant results. Among our findings:

• Increasing the number of gender-diversity initiatives is not enough. Although having a critical mass of measures is important, volume alone does not explain women’s representation in top management: 52 percent of the companies in our sample implemented more than 50 percent of the measures, but only 24 percent of them reported having more than 20 percent of women in top management positions.
• A mere 7 percent of the companies in our sample ranked diversity among the top three priorities on their strategic agenda.
• Of the 2,200 employees we surveyed, more than 88 percent said they do not believe their company is doing what it takes to improve gender diversity, and 62 percent of them do not know how to contribute to gender diversity.
• Regarding the effectiveness of gender-diversity programs, only 40 percent of respondents reported that these were well implemented in their companies—that is, programs had clear follow-up processes in place, they were assessed on a regular basis, and their effectiveness was evaluated at various levels of the organization.

Previously, we outlined a comprehensive gender-diversity ecosystem that companies can put in place to increase women’s representation at each level of the organization. Building on this, our 2016 research shows that three game-changers distinguish best-in-class companies:

• Persistence. Best-in-class companies initiated diversity programs earlier, indicating that it takes time to effect tangible, sustainable results.
• CEO commitment, cascading down to all management levels.Companies that have built gender diversity successfully at the leadership level are twice as likely to place gender diversity among the top three priorities on their strategic agenda, to have strong support from the CEO and management, and to integrate gender diversity at all levels of the organization.
• Comprehensive transformation programs. Best-in-class companies have initiated change programs that ingrain gender diversity in all aspects of the business. Specifically, those companies are more likely to have change agents and role models at all levels of the organization; they also have developed and communicated a compelling change story to support the programs, policies, and processes they have put in place.

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We believe it will take government and business-led interventions to create an environment that offers women better opportunities; enables them to train for and work in skilled, better-paying roles; reshapes social norms and attitudes; and supports work–life balance. To achieve this, companies will need to transform themselves by reevaluating their traditional performance models and by challenging the long-term viability of their prevailing leadership styles.

About the author(s)
Sandrine Devillard and Sandra Sancier-Sultan are senior partners in McKinsey’s Paris office, where Alix de Zelicourt is a consultant and Cecile Kossoff is the director of knowledge dissemination and communications.

Editor's Note: Kathy Carter has played soccer since childhood, including for the College of William and Mary. She was a founding member of Major League Soccer in 1996 and served as vice president of corporate marketing for MLS for six years. She has also been the US representative on FIFA's Committee for Women's Football and the FIFA Women's World Cup. Carter was most recently the president of Soccer United Marketing, where she managed the business operations for MLS' commercial subsidiary. The views expressed here are solely the author's.
(CNN)-Since the first day I walked onto the soccer field, when I was 7 years old, I have been questioned and doubted.
I was asked: Do you have what it takes to play this sport? Are you tall enough to be a goalkeeper? Are you quick enough? Is your skin thick enough for you to take a loss and bounce back stronger?
At every stage, I heard questions -- some spoken aloud, some whispered -- about me, my talent, my body, my character. This line of questioning starts at a young age for girls. Unfortunately, it doesn't end when we leave the soccer field, or as we become adults. Just the opposite, in fact. For women, it becomes our norm as we enter the workplace. Soccer gave me the confidence to work through the added pressure, prove the doubters wrong, and resolve to clear a smoother path for future generations of women.

I was fortunate to have played for supportive coaches and with tremendous teammates. Not every young woman is so lucky. My dad was one of my first coaches; he did this job with a "how to" book in his hands and baseball cleats on his feet. In high school, I was named an All-American, and I went on to start for a nationally ranked team at the College of William and Mary.
When I was finishing my final college season in 1990, there was no professional pathway for female players in the United States. No pro leagues to join, no National Women's Soccer League to aspire to, and no post-collegiate female players to look up to. So I continued to play in amateur adult leagues. My career as a soccer player came to an end not because I wanted it to, but because there was no option for women to make a career out of playing the best sport in the world here at home.

I didn't always know my future was in soccer, but what I did know was that I loved the game. Then, good fortune struck when a friend from an opposing team introduced me to members of the 1994 World Cup Organizing Committee and I was given a shot to make the game my profession. I've never looked back.
I'm very proud of my playing career and my career as an executive in the game. But I have news for anyone reading this: The doubting questions have never stopped. As I made the transition from player to executive, the questions just changed.

Would men take a woman as president of US Soccer seriously? Would people listen to her? Could she lead such a large and high-stakes organization?
I've answered these questions in business and plan to do so in a new role: I am now running for another leadership position in soccer, that of president of the US Soccer Federation. Before I began this effort, my journey was, like most people's, outside the glaring lights. Now that I'm in the race, even though I bring both soccer and relevant business experience to the table, questions abound.

Does she have enough soccer experience? Is her business experience the right kind? Is she her own person? Has she done enough as a woman in the game?
In the international soccer community, out of FIFA's 211 member associations, there are only a few female leaders. In the United States, there are several women serving as leaders of their respective sports, but it is not nearly enough.

Kids dream of representing our country on the global stage as players, coaches, referees, executives or administrators. I want to show them, especially young girls, that any of these options are within their grasp.
If elected, I'll be the first female president of US Soccer, but I'll fight for all the things any good leader wants, confronting challenges, such as rebounding from the failure of our men's national team to qualify for the 2018 FIFA World Cup and remedying our confusing youth soccer landscape. I'm optimistic about the future because the American soccer community is talented, committed and ready to deeply assess what's wrong and work together -- plus our women's national team is heading to France in 2019 to defend our world championship. It is a time of change and we must focus on unity and collaboration to drive progress.

This work starts with changing the federation's culture, prioritizing improvements in youth soccer, growing the adult game, building a new technical department to support all our national teams, and going all-in on the women's game.

I know the doubts I've faced throughout my career are faced by many women -- most women. I know because a lot of them tell me. Like them, I have responded the only way I know how: I've worked harder to be more prepared, to see every angle, to avoid every error possible. I've learned through successes and yes, sometimes through failures, the importance of listening, working constructively, setting ambitious goals, and helping everyone succeed together.

Inside me is still the 5-foot-5 goalkeeper about whom no one ever said at first glance, "Wow, she's going to be great." I had to earn everything I got and I am extremely proud of that.

I'm also proud of the female teammates I've had in business, another lesson from the game. Throughout my career, I've mentored, supported and counseled hundreds of young women building their own careers in sports. Today, these women are part of a growing network of successful women who are rising through the ranks of professional sports leagues, front offices, sports apparel companies, TV networks and sports marketing agencies. And, I have benefited from their wisdom, support, hard work and professionalism.

Among the things that excite me most about the possibility of leading US Soccer is the opportunity to address diversity and equality head on. I want treatment of our girls and women to be equal across the sport and from top to bottom -- from pay to training staff to field conditions and beyond.
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I want to take all that I've learned from my own experiences and from these female teammates and use it to invest in helping all our national teams continue to inspire the country and the world. I want generations of young girls and boys to have soccer -- and the lessons from soccer -- running through their veins.

• A new law in Iceland making it illegal to pay women less than men came into effect on January 1, 2018. 
• Companies will now have to obtain certification for demonstrating equal pay. 
• Iceland has been ranked the best in the world for gender pay equality for 9 years in a row.

Iceland has made it illegal to pay men more than women.
A new law enforcing equal pay between genders came into effect on January 1, 2018, according to Al Jazeera.
Under the legislation, firms that employ more than 25 people are obliged to obtain a government certificate demonstrating pay equality, or they will face fines.
The law was announced on March 8 on International Women's Day 2017 as part of a drive by the nation to eradicate the gender pay gap by 2022.
Dagny Osk Aradottir Pind, of the Icelandic Women's Rights Association, told Al Jazeera: "The legislation is basically a mechanism that companies and organisations ... evaluate every job that's being done, and then they get a certification after they confirm the process if they are paying men and women equally."
​She added: "It's a mechanism to ensure women and men are being paid equally.
"We have had legislation saying that pay should be equal for men and women for decades now but we still have a pay gap."
The Nordic country, home to more than 323,000 people, has been ranked the best in the world for gender equality by the World Economic Forum for nine years in a row.
The Global Gender Gap Report evaluates gender equality in a country using indicators including economic opportunity, political empowerment, and health and survival.
The new legislation was supported by Iceland's centre-right coalition government, as well as the opposition - nearly 50 per cent of the lawmakers in parliament are women.
Ms Aradottir Pind added: "I think that now people are starting to realise that this is a systematic problem that we have to tackle with new methods.
"Women have been talking about this for decades and I really feel that we have managed to raise awareness, and we have managed to get to the point that people realise that the legislation we have had in place is not working, and we need to do something more."
The UK reported a 16.9% pay gap between men and women in 2017.