Corporate America still has a long way to go to achieve gender equality in the workplace.

According to a comprehensive study by Lean In and McKinsey & Company, Women in the Workplace 2015, women remain underrepresented at American companies, from entry level to the C-suite.  The greatest disparity occurs at senior levels of leadership.

The study’s authors offer several key findings.  For one, the leadership ambition gap persists and women find the path to leadership disproportionately stressful.  Another finding is the uneven playing field women experience: The study concludes that women are almost four times more likely than men to think they have fewer opportunities to advance because of their gender.  Senior-level women believe their gender is a greater disadvantage than entry-level women do, and are significantly less satisfied with their role, opportunities for advancement, and career than their male counterparts.

In addition, while a majority of companies offer flexibility and career development programs, many women and men are not using them, out of fear of being penalized. More than 90% of women and men believe that taking extended family leave will hurt their position at work, and more than 50% believe it will hurt them a great deal.

Yet another key finding points to the different networks that men and women have. With men having predominantly male networks and men holding more senior leadership positions, women may end up with less access to senior-level sponsorship.  Inequality at home, in which women report having more responsibility for childcare and household chores, also affects the challenges women face in juggling home and work responsibilities.

Sheryl Sandberg wrote this about the study in The Wall Street Journal, on September 30, 2015: “[A]t the current pace of progress, we are more than 100 years away from gender equality in the C-suite.  If NASA launched a person into space today, she could soar past Mars, travel all the way to Pluto and return to Earth 10 times before women occupy half of C-suite offices.  Yes, we’re that far away.”

The progress we’ve made toward gender equality belies the studies that show that greater diversity and inclusion are better for business and can provide a competitive advantage.  According to the Women in the Workplace 2015 study, companies say that diversity is important and they want more women in leadership positions.  So what should companies do to achieve greater gender diversity?  Lean In and McKinsey & Company make some suggestions, although they note to that there is no “one size fits all” solution.

First, they recommend that companies track key metrics (e.g., performance reviews and promotions, compensation across women and men in similar roles, and attrition) to determine what is working and where they can improve.

Second, senior leadership should invest time and money in a genuine commitment to gender diversity (e.g., setting gender-specific objectives and holding leaders accountable for reaching them).

Third, organizations should train their employees to identify and counteract gender bias in hiring and performance reviews.

Fourth, employee programs should not inadvertently penalize participants, and management should support the employees’ decisions to utilize such programs, such as family leave.

Finally, companies should create a level playing field for women and implement systems that support women (e.g., formal mentorship and sponsorship programs and networking events).

The report serves as a good reminder that gender equality continues to lag. Awareness is important, but action even more so.