Here's an experiment that will take a little courage. Next pay day, offer to swap your salary slip with that of a colleague of the opposite sex who does the same or a similar job to you.
In an ideal world, this would confirm that you work for a fair-minded employer, one that sticks to the rules on equal pay for men and women. More likely, however, the exercise will open up a hornet's nest of envy and hostility.
"In a workplace where people don't discuss their wages openly, unequal pay flourishes," says Rob Holdsworth of the Equal Opportunities Commission.
And that's the nub of the problem. Recent research from the Chartered Institute of Personnel and Development has revealed that as many as a third of companies, mainly in financial services and the City of London, actively dissuade staff from discussing wages and bonuses in the office - often insisting on confidentiality in their contracts.
Such policies are a major hindrance to efforts by the commission to help close the gap between the sexes.
"At the moment, the gender pay gap [for average earnings] in the private sector is 22.3 per cent," says Mr Holdsworth. "This is higher than in the public sector, where the pay gap is 13.5 per cent."
The difference is down to the greater degree of secrecy surrounding salaries in private companies, the commission says. In the public sector, pay scales are widely published for all to see.
But across all industries, a gulf continues to exist between men's and women's salaries. The figures for average hourly earnings show that, last year, men earned £14.62 and women £12.11.
Take the weekly average pay for a health professional, such as a doctor or hospital manager, and the discrepancy becomes even more marked: £1,332.60 for men, £935 for women.
Bridget Bodman, a former accountant at the packaging manufacturer API Group, won £25,000 compensation last month when an employment tribunal ruled that her male successor in the job unfairly earned £9,000 more for doing the same tasks, as well as receiving an £8,640 car allowance and other benefits.
Employment lawyers warn that cases like this are likely to lead to more claims relating to pay and sex discrimination, and that companies need to address such issues urgently.
The public sector, at least, is already gearing up for change. In April, a new rule called the Gender Equality Duty (GED) will force local councils, hospitals, schools and the police to promote fairness in relation to pay and recruitment, among other targets.
Rather than relying, as now, on individuals to highlight pay discrimination, the onus will be on public bodies to enusre there is no inequality. In particular, employers in the sector will have to review their policies in areas where men and women do the same job, or jobs of similar value.
But private companies will play no part in the GED, since the commission's focus is on how gender equality affects public policy.
"The only way that the private sector is involved is when [its] companies are contracted for work with a public body," says Mr Holdsworth. "By having an open, non-discriminatory approach to pay, [a private company] can have a much better chance of winning tenders."
There are organisations in the private sector that launch similar pay reviews, but commission research shows these are rare.
For many, the question is still, why do women earn less than men more than 30 years after the Equal Pay Act came into force in 1975? The commission believes one reason is "occupational segregation", which corrals men and women into different careers early on.
"This is down to gender stereotyping, which starts at school with careers advice," says Mr Holdsworth. "For example, men more often go into finance and IT."
In an commission survey of 16- to 18-year-olds, 80 per cent of girls said they would, or might, be interested in a traditionally male job. But just 15 per cent had actually received any advice or information on work experience in these areas.
Many women also damage their earning potential by taking career breaks to have children. Figures from the Office for National Statistics show that, in their 20s, the average earnings gap between men and women is only around 3 or 4 per cent. However, the gap widens when people reach their 30s and start families.
"Many women move to part-time work," Mr Holds-worth points out. "There's the long hours culture to blame too: often it's just not possible [to go on working in a job if you have a child]."
If you think you're a victim of pay discrimination at work, the commission recommends you first raise the issue with your immediate manager and ask for a comparison between your salary and that of somebody else doing the same job.
There's no law that forces companies to agree to this, but if your request is turned down, you can ask that your employer fills in an "equality pay questionnaire". Again, though, there is no legal obligation to do this.
If you hit a brick wall, and have no trade union to act on your behalf, you could consider seeking legal advice with a view to taking your case to an employment tribunal. But this is a stressful process, the commission warns.