Why does the UN use HDI instead of GDPpc used by the EU or OECD to measure development?

Because development is such a complex concept that cannot be measured by any single indicator alone.

Because GDP only measures the market value of production and neglects unmarketed goods such as sunshine or clean air.

Because GDP is a market-based measure and many UN countries do not have a market economy.

Because HDI equates the value of one year of education at Harvard with one year of education at the poorest African university.

Because HDI is more stable and not so much affected by the actions of incompetent or corrupt leaders.

Because the composition and weights of HDI components is decided by a few leaders instead of millions of producers/consumers.