PapayaMobile, a global mobile-technology firm I founded in 2008 in Beijing, has a female-to-male employee ratio that's 50/50 on the dot. We haven't been able to identify any reason why female employees aren't as great a fit as male employees.

We've set an example by hiring and promoting deserving female executive-level engineers. Outside of the office, our reputation for fairness is often spread by word-of-mouth among prospective candidates, which provides us with a deeper pool of talented candidates to hire, regardless of...