Why is the Kuznets curve inverted?

The Kuznets curve is inverted because, initially, as the income per capita increases the income inequality keeps rising. After a certain point of economic development, although the income per capita keeps increasing, the income inequality goes down. Hence the Kuznets curve is inverted. You can read about the Kuznets Curve – Explanation of the Kuznets curve, its Criticisms in the given link.

Further readings:

1. Inflation in Economy- Types of Inflation, Inflation Remedies [UPSC Notes]
2. Indian Economy Notes For UPSC Exam [Download PDFs]