A new study published in the American Sociological Review found evidence of a double-digit pay gap between bisexual people and their straight counterparts -- and the report suggests stereotyping and discrimination play a part.

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Bisexual men, on average, earn 11 to 19 percent less than straight men, and bisexual women earn 7 to 28 percent less than straight women, according to "Sexual Orientation in the Labor Market" by Trenton D. Mize, a Ph.D. candidate in Indiana University's Department of Sociology.

"Sexual minorities face diffusely negative sentiments, being viewed generally unfavorably and stigmatized as non-normative in most societal contexts," Mize noted in the study. "Many sexual minorities also face assumptions of lower competence compared to heterosexual individuals, a key factor influencing hiring decisions.

The pay gap for bisexual men and women differs from the gaps seen between straight employees and their gay and lesbians counterparts. While gay men make 5 percent less than straight men, lesbians, on average, make more than straight women.

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Mize draws particular attention to the bisexual wage gap, because it is a bit harder to explain -- without factoring in stereotyping and discrimination. He partially attributes the wage gap for gay men to "different rates of marriage and childrearing" and the "preferential treatment" afforded to married men and fathers. Lesbians make more than their straight counterparts, according to the study, due to their lower rates of motherhood. However, these reasons do not fully explain the pay inequality that bisexual Americans experience.

“All non-heterosexual individuals face negative stereotypes and -- sometimes -- discrimination. However, bisexual men and women face additional stereotypes that can be particularly disadvantaging,” Mize told NBC OUT.

“One thing that has driven an increase in social acceptance of gay men and lesbian women is an increase in perceptions that they are sexual orientations someone is born with, or have no choice in. However, because bisexual men and women are romantically interested in both men and women, individuals view them as having some degree of choice to their sexual orientation. Perceptions of choice are important, because people are more likely to discriminate against a person if they believe that person has a degree of choice to their disadvantaged status," Mize added.

Among the stereotypes that bisexual men and women face, according to Mize, are that they are “immature or dishonest about their sexual orientation.” This, Mize said, can “culminate into general perceptions that bisexual men and women are less competent and capable.”

So, how does the bisexual wage gap get closed? Mize argues the most effective action would be a federal non-discrimination law which includes sexual orientation. Second to that, would be changes in social perceptions of bisexual men and women.

However, Mize is not optimistic that we’ll see federal non-discrimination legislation over the next four years.

“It is difficult to say for sure, because there are mixed messages coming from the future President and from the future Vice President about issues of sexual orientation,” Mize noted. “Having lived in Indiana for the last five years, though, I can say that I am not optimistic about Mike Pence championing legislation that would benefit LGB employees.”

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