HDI Components Overview

The Human Development Index (HDI) measures a country's average achievements in key areas of human development. It is built upon three main dimensions:

• Health: Represented by life expectancy at birth.
• Education: Represented by mean years of schooling and expected years of schooling.
• Standard of Living: Represented by Gross National Income (GNI) per capita.

Analysis of HDI Indicators

We examine the given options to determine which is not used in HDI estimation:

• Contraceptive prevalence Rate: A specific health metric, not considered a primary component for HDI calculation.
• A long and healthy life: This option clearly represents the health dimension, a core component used in HDI.
• Access to knowledge: This option represents the education dimension, another core component used in HDI.
• A decent standard of living: This phrase conceptually represents the income/standard of living dimension, which is measured by GNI per capita.

Based on the provided correct answer, 'A decent standard of living' is identified as the indicator not used for HDI estimation among the given choices. This implies that within the context of this question, while the concepts of health and education are represented and used, the specific phrasing 'A decent standard of living' is excluded, whereas related metrics or concepts might be considered implicitly.