The study looked at how the value of China's currency, the RMB, affects trade between China and the United States from 1990 to 2010. The researchers found that the RMB exchange rate does impact trade balance, but not as much as the GDP of both countries. There is a pattern where trade balance initially worsens before improving, known as the J-curve effect. To improve trade balance, it is suggested to adjust economic and export structures and allow the RMB exchange rate to float freely.