During last night’s Oscar ceremony, Best Supporting Actress winner Patricia Arquette used her acceptance speech to rail against unfair pay for women:
To every women who gave birth to every taxpayer and citizen of this nation, we have fought for everybody else’s equal rights. It’s our time … to have wage equality once and for all and equal rights for women in the United States of America.
The wage equality that Arquette is referring to is the gender wage gap—the difference between male and female earnings expressed as a percentage of male earnings. Because she frames the issue as a matter of equal rights, Arquette presumably believes that the problem is caused by intentional discrimination.
The gender wage gap certainly exists, but there is considerable debate about the size of the gap and whether it is caused primary by discrimination or by other factors, such as education and work hours. Much of the confusion is caused by the use of misleading statistics by politically motivated groups. For example, last night the Department of Labor (DOL) posted on their Twitter account: