There is no gender wage gap

https://www.prageru.com/courses/political-science/there-no-gender-wage-gap

If women only made 77 cents to a man dollar, why don't more business only hire women?
Wages are the biggest cost to a business, if women made less then if a company only hire women then the company would save a quarter of the cost and to the bottom line.
The feminist, celebrities and politicians telling people that the gender wage gap.
I believe that they have a math problem. The 77 cents on the dollar is calculated by using the medium of women that working full-time as of men working full-time. If a man earns 40,000 and a woman earns 30,800 then divided the woman salary with the man then you have a 77 cents per dollar idea.
This does not show gender wage injustice. They don't show occupation, position, education, or hours per week.
American Association of Women study shows that the wage gap goes down to 6.6 cents when you factor in different choices men and women make. The key word is choice.
This is not based on women making less per hour but on the jobs choices that men and women make.
In 2009, the US Department of Labor examined 50 peer reviews studies. They concluded that the oft-cited 23 cents wage gap may be almost entirely the results of individual choices being made by male and female workers.
Georgetown University provided what were the five best major to make money and the percentage of men and women that were majoring in these fields.
The number one major was Petroleum Engineering, 87% males got a degree in this.
The number two major was Pharmaceutical sciences, 48% males got a degree in this.
The number three major was Mathematics and Computer science, 67% males got a degree in this.
The number four major was Aerospace Engineering, 88% males got a degree in this.
The number five major was Chemical Engineering, 72% males got a degree in this.
If you can observe, only one of these majors when women got more degrees than men by a few more percentage points.  
We will look at the five worst paying majors.
The number one was Counseling and Psychology, 74% females received this degree.
The number two was Early Childhood Development, 97% females received this degree.
The number three was Theology and Religious Study, 66% males received this degree.
The number four was Human services and Community Organization, 81% females received this degree.
The number five was Social Work, 88% females received this degree.
The women own four of the five worst paying degrees.
This shows that men and women make different career choices.
If you look at the nursing field. Males make 18% more in general because they go for specialties, work longer hours, willing to relocate for higher pay in cities that pay more.
Professor Aikens said about the nursing field, "career choices and educational differences explains most, if not all, the gender gap in nursing." 
Why is there is gap? No one knows for sure.
There are so many variables that drives wages that no single study can cover them all.
Some studies talk about dangerous work areas like in oil ships, men work there.
Men are more likely to work longer without advance notice.
Harvard Economist, Claudia Goldin says even if the two lawyers had everything alike, if one of them are wanting to be on call and work long hours, then that person will get a higher wage.
This is not sexism but it is common sense.