What factors contribute to the gender pay gap?
Women are, on average, more agreeable than men. This could be relevant when negotiating a salary for a particular role.
Young men are more likely than young women to relocate for work. This would open up more opportunities for a higher salary.
Women generally prefer to take softer skilled jobs, rather than pursuing careers in eg engineering
Men are more likely than women to work in dangerous jobs, which are typically compensated with higher wages.
In many professions, men are more likely to be promoted than their female colleagues.
Women take more time on maternity leave than men take as paternity leave.
On average, men work more hours than women.
Many career-focused women find that starting a family changes their priorities, and realise that there is more to life than just working all the time.
In some industries, sex-based discrimination in the workplace has pushed women away.
Even in societies which strive to ensure equality of opportunity, men and women still sort themselves into the roles they prefer, rather than roles that would achieve equal pay.
Men are more likely than women to apply for a job when they don't necessarily have all of the listed skill requirements. Women tend to only apply for jobs where they have most or all of the skills already.
Men are more likely to take jobs that require a large sacrifice, eg executive jobs that are demanding on time / stress / quality of life
The gap begins before the workplace: in higher education, women on average choose to study lower paying fields, or lower paying specialities in higher paying fields.