quality:correction
Earnings gap

Studies have concluded that on average women earn lower wages than men worldwide. Some people argue that this results from widespread gender discrimination in the workplace. Others argue that the wage gap results from different choices by men and women, such as women placing more value than men on having children, and men being more likely than women to choose careers in high paying fields such as business, engineering, and technology.

Eurostat found a persistent, average gender pay gap of 27.5% in the 27 EU member states in 2008. Similarly, the OECD found that female full-time employees earned 27% less than their male counterparts in OECD countries in 2009.

In the United States, the female-to-male earnings ratio was 0.77 in 2009; female full-time, year-round (FTYR) workers earned 77% as much as male FTYR workers. Women's earnings relative to men's fell from 1960 to 1980 (56.7–54.2%), rose rapidly from 1980 to 1990 (54.2–67.6%), leveled off from 1990 to 2000 (67.6–71.2%) and rose from 2000 to 2009 (71.2–77.0%). As of the late 2010s, it has decreased back to around 1990 to 2000 levels (68.6-71.1%). When the first Equal Pay Act was passed in 1963, female full-time workers earned 48.9% as much as male full-time workers.

Research conducted in Czechia and Slovakia shows that, even after the governments passed anti-discrimination legislation, two thirds of the gender gap in wages remained unexplained and segregation continued to "represent a major source of the gap".

The gender gap can also vary across-occupation and within occupation. In Taiwan, for example, studies show how the bulk of gender wage discrepancies occur within-occupation. In Russia, research shows that the gender wage gap is distributed unevenly across income levels, and that it mainly occurs at the lower end of income distribution. The research also found that "wage arrears and payment in-kind attenuated wage discrimination, particularly amongst the lowest paid workers, suggesting that Russian enterprise managers assigned lowest importance to equity considerations when allocating these forms of payment".

The gender pay gap has been attributed to differences in personal and workplace characteristics between men and women (such as education, hours worked and occupation), innate behavioral and biological differences between men and women and discrimination in the labor market (such as gender stereotypes and customer and employer bias). Women take significantly more time off to raise children than men. In certain countries such as South Korea, it has also been a long-established practice to lay-off female employees upon marriage. A study by Professor Linda C. Babcock in her book Women Don't Ask shows that men are eight times more likely to ask for a pay raise, suggesting that pay inequality may be partly a result of behavioral differences between the sexes. However, studies generally find that a portion of the gender pay gap remains unexplained after accounting for factors assumed to influence earnings; the unexplained portion of the wage gap is attributed to gender discrimination.

Estimates of the discriminatory component of the gender pay gap vary. The OECD estimated that approximately 30% of the gender pay gap across OECD countries is because of discrimination. Australian research shows that discrimination accounts for approximately 60% of the wage differential between men and women. Studies examining the gender pay gap in the United States show that a much of the wage differential remains unexplained, after controlling for factors affecting pay. One study of college graduates found that the portion of the pay gap unexplained after all other factors are taken into account is five percent one year after graduating and 12% a decade after graduation. A study by the American Association of University Women found that women graduates in the United States are paid less than men doing the same work and majoring in the same field.

Wage discrimination is theorized as contradicting the economic concept of supply and demand, which states that if a good or service (in this case, labor) is in demand and has value it will find its price in the market. If a worker offered equal value for less pay, supply and demand would indicate a greater demand for lower-paid workers. If a business hired lower-wage workers for the same work, it would lower its costs and enjoy a competitive advantage. According to supply and demand, if women offered equal value demand (and wages) should rise since they offer a better price (lower wages) for their service than men do.

Research at Cornell University and elsewhere indicates that mothers in the United States are less likely to be hired than equally qualified fathers and, if hired, receive a lower salary than male applicants with children. The OECD found that "a significant impact of children on women's pay is generally found in the United Kingdom and the United States". Fathers earn $7,500 more, on average, than men without children do.

There is research to suggest that the gender wage gap leads to big losses for the economy.