The researchers found that official data on household income in China is inaccurate due to underreporting and non-participation by high-income groups. By using a different method, they estimated that total household income in 2008 was higher than reported, with the wealthiest 10% receiving a large portion of unreported income. The income gap between the richest and poorest households is much larger than previously thought, indicating higher levels of inequality. The researchers suggest that corruption is a significant issue, as unreported income grew faster than the national income, highlighting the need for institutional reforms to prevent corruption from hindering economic development and social harmony.