Who has to 'lean in' for equal gender representation in leadership roles?

Even though women surpass men in university graduation rates and other skill-based gains, the Conference Board of Canada (2011) found it will take over 151 years for women and men to achieve parity in middle management, let alone senior leadership. Sheryl Sandberg's book, Lean In (2013), invigorated a worldwide conversation about the representation of women in leadership roles.