The share of patents going to women has risen over time, but is still less than 15 percent of the total, according to a study by several economists published in a working paper called “The Lifecycle of Inventors.” At the current rate of convergence, it will take another 140 years for women to obtain 50 percent of granted patents, the study found.

The study's results were included in remarks delivered recently by U.S. Patent and Trademark Office Director Michelle Lee at a University of Texas roundtable entitled “Innovation: Does Gender Matter?”

Lee, who is the first woman ever to lead the PTO, said the agency does not collect demographic data on who applies for patents, but that studies consistently conclude that women are named as inventors on patents at astonishingly low rates.