Women are scarce among America's top-paying jobs

Tuesday is Equal Pay Day, a reminder of the stubborn income inequality between men and women, also known as the gender pay gap.

Overall, a woman makes about 76 cents for every dollar a man does.

One reason for the pay differential, which increases with age, is how men and women sort into occupations and industries with varying earnings potential.

Among the country's highest-paying jobs, women are substantially underrepresented nearly across the board, according to a new report by LinkedIn. Even when comparing the sexes with the same job title at the same company and using similar education and experience, the gap persists. The networking site analyzed the gender breakdown among the top 100 highest paying jobs in America based on its own salary data.

In the most lucrative professions, women make up less than 30 percent in each role. Orthopaedic surgeon, for example, was the highest-paying job overall and has nearly 13 men to every woman in the field.

The shift in favor of women's earning power has been pronounced in the so-called STEM fields of science, technology, engineering and mathematics, according to a separate analysis by Federal Reserve economists.

Still, women are highly underrepresented in STEM careers as well. Six of the top 10 roles with the lowest female representation were tech jobs, LinkedIn said.

Although more women are pursuing STEM jobs, "You see a stark drop-off in the number of women every step of the way, in terms of advancement," said Paul Ko, LinkedIn's head of economic graph analytics. "The pipeline has virtually evaporated."

Of chief technology officers, a job that pays a median base salary of $190,000, only 5 percent were women.

The gender gap was smaller, or closed, when it came to jobs in human resources, marketing and health care. There were just three top-paying positions — all in human resources — where the number of women exceeded the number of men.