Not everyone agrees that there is a true gender pay gap. For starters, the calculations compare the salaries of all working women to all working men, yet these women and men don't all hold the same jobs. That is, the figure isn't comparing male doctors with female doctors or male electricians with female electricians. And even if it were, most employees have different educational and employment backgrounds, two factors that greatly impact salary [source: Glynn].
Another point to keep in mind is that both women and men tend to cluster around certain occupations. About 45 percent of all working women are employed in just 20 fields, including secretaries and teachers; among men, one-third work in the top 20 male occupations, which include managers and supervisors. Overall, the cluster of occupations women favor tend to pay less than those favored by men. Some experts say such job-clustering accounts for about half of the gender pay gap [source: Glynn].
Childcare is another reason men and women don't always earn the same amount of money when working at the same occupation. If a woman takes time off after giving birth, for example, she will have less tenure than her male counterparts when she returns to the workforce, and may lose out on wage increases. Some experts add that more women than men seek jobs that are close to home and that offer flexibility and personal fulfillment, which creates competition for these types of jobs and thus holds down wages. Men are also more likely to take on jobs that are dangerous or physically demanding, but offer greater pay, like truck driving or construction work [source: Farrell].
Critics also point out that when you compare the wages of men and women with similar credentials who are working in similar fields, there isn't much of a wage gap at all (although the men will almost always out-earn the women). A few examples: Among elementary school teachers and human resources administrators the pay gap is 1 percent; for registered nurses and computer systems administrators it's 2 percent; for software developers and construction project managers it's 4 percent [source: PayScale].
Nevertheless, some say that after controlling for similar education, occupation and work experience and race, there is still a 38 percent wage gap that cannot be explained by measurable factors [source: Holmes and Corley]. Of the 534 occupations tracked by the Bureau of Labor Statistics in 2016, a scant four paid women more than men. These included sewing machine operators and fast food workers.