The study looked at how education and income inequality are connected in different countries. They used data from 101 countries over 40 years to see how changes in education levels affect income inequality. The results showed that more equal education can help reduce income inequality in many countries. However, in wealthier countries, other factors like development level and trade openness play a bigger role. In poorer countries, unfair income distribution makes it harder to improve education equality. This creates a cycle where education and income inequality reinforce each other.