Lesbian employees in the UK earn 8% more than their straight counterparts, while gay men are paid 5% less than straight men, according to a study.
The study commissioned by the World Bank and the economic research institute IZA World of Labor found that sexual orientation is seemingly affecting job access, satisfaction, earning prospects and interaction with colleagues.
Studies for the period 1989–2014 for lesbian workers suggest that the earnings differences between lesbians and heterosexual women of comparable education, skills, and experience vary by country.
In the US, lesbians' pay is 20% higher than straight women, while it is 15% higher in Canada and 11% higher in Germany.
While France and Sweden have no pay gap based on sexual orientation, lesbian employees earn 28% less than their female heterosexual counterparts in Australia and 8% less in Greece.
"Lesbians may realize early in life that they will not marry into a traditional household and thus decide to invest more heavily in a market-oriented education," the report says, analysing reasons for lesbians' higher pay.
"Lesbians may be willing to make a series of carrier-oriented decisions—such as staying in school longer, choosing a degree that is likely to lead to a higher paying job, and working longer hours—that differ from those they would have made had they adopted traditional gender-based household specialisation roles."
In the case of gay men, they are 16% less paid than heterosexual men in the US. The gap is 13% in Sweden, 12% in Canada and 9% in Germany.
"It is hypothesized that the labor market values gay men's characteristics less than those of heterosexual men, and that the difference in earnings is attributable to the failure of gay men to conform to traditional gender roles," the report adds.
The study also found that less than 20% of countries involved in the study have adopted sexual orientation anti-discrimination laws in employment, and 2.7 billion people live in almost 80 countries where being gay or lesbian is a crime.