A business degree, even from one from a top school in the country, won't be enough to protect women from the gender gap in compensation.

A report Bloomberg Businessweek published Tuesday found that the difference in pay for men and women swells as time goes by. Both groups leave their MBA programs earning about the same -- men's $105,000 to women's $98,000 -- but the split becomes more exacerbated years later. By the time they're six to eight years out of school, median compensation for men is $175,000, and $140,000 for women. For the latter, that rounds out to about 80 percent of men's paychecks, proving unfortunately that the roughly 78 cents women make to a man's dollar still holds up.

The study counters arguments that the pay gap between men and women results from a discrepancy in education and skills, Businessweek reporter Natalie Kitroeff told HuffPost Live on Wednesday. "We're looking at them coming out of the same schools, in the same years," Kitroeff said. "It was surprising to find that there was such a persistent gap, and we found this across every single industry."

Men gain the most ground in year-end bonuses. When those are excluded, the pay gap shrinks. Women who graduated Columbia's business school between 2007 and 2009, for example, earned a median of $170,000 in 2014, while men raked in $270,000. The difference in base salaries, though, was just $30,000.

The study's findings also reject the notion that the gap stems from women choosing to go into fields that pay less. Generally, men do enter the more lucrative industries, including consulting, real estate and finance, at higher rates -- 43 percent of men versus 32 percent of women -- but "even when women went into the highest-paying industries, they were paid less," Kitroeff said.

And let's not forget that the gender pay gap starts way before higher degrees. At the most elite colleges in the U.S., male alumni far outearn their female classmates, with Harvard men earning an average of $53,600 more than women 10 years after they start their undergraduate studies.