The study looked at the difference in wages between men and women in China's cities. They used data from a survey in 2009 and different methods to analyze the wage gap. They found that men generally earn more than women, and a big part of this difference is not easily explained. When they accounted for bias in the data, they found that discrimination played a bigger role in the wage gap. They also found that the type of job and how long someone has been working are the main factors contributing to the wage gap, followed by education level.