What are the two "education variables" used as a part of the HDI index and why does education matter when analyzing a nation's social and economic development?

Literacy rate and health.

Explanation:

The HDI states the three variables such as life expectancy, per capita GDP, and education indicators as adult literacy which is for primary, secondary, and tertiary enrollment in schools and colleges. Education has seen an important issue in the development of the nation's economy and for the growth of per capita income and social status of the country. It's also important for the health and wellbeing of the country as the educated class is more literate and health-conscious.

Bis the answer i believe