For the 2025 fiscal year, countries are classified into four income groups based on their Gross National Income (GNI) per capita, calculated using the World Bank Atlas method. Low-income economies have a GNI per capita of $1,145 or less, while lower middle-income economies fall between $1,146 and $4,515. Upper middle-income economies are those with a GNI per capita between $4,516 and $14,005, and high-income economies are classified as having a GNI per capita exceeding $14,005.
The Gini coefficient is a widely used measure of inequality, named after Italian statistician Corrado Gini. The Gini coefficient ranges from 0 to 1, with higher values indicating greater inequality. This measure is sometimes expressed as a percentage from 0 to 100%, referred to as the “Gini Index.” A Gini value of 0 represents perfect equality, where everyone has the same income, while a value of 1 signifies perfect inequality, where one individual receives all income and others receive none.
Median income is a key metric for understanding a nation’s income distribution. It represents the income level that divides the population into two equal groups: half of the population earns more than the median, and the other half earns less. This makes it a better reflection of the typical income compared to the average, or mean, which can be skewed by extremely high or low values. The data used is measured in international dollars at 2017 prices, adjusting for inflation and cost of living differences between countries, which ensures a more consistent comparison of income levels globally.
The Human Development Index (HDI) is a widely recognized measure of human development that reflects the well-being of individuals. It is based on three dimensions: a long and healthy life, measured by life expectancy at birth; knowledge, assessed through expected years of schooling for children and average years of schooling for adults; and a decent standard of living, determined by Gross National Income (GNI) per capita. These dimensions are normalized and aggregated to create a score ranging from 0 to 1, enabling the classification of countries based on their development levels.
Gross Domestic Product (GDP) per capita is a key economic indicator that measures the average economic output per person, reflecting the standard of living in a country. Life expectancy at birth, meanwhile, is a crucial metric indicating the average number of years a newborn is expected to live, serving as a vital sign of public health and quality of life. Generally, there is a positive correlation between GDP per capita and life expectancy, as higher income levels often lead to improved healthcare access, better nutrition, and overall enhanced living conditions.
This visualization is created by Khairong on 13/10/2024.
Data sources:
1. World Bank (2024): World Bank Income Groups;
2. World Bank Poverty and Inequality Platform (2024): Gini Coefficient;
3. World Bank Poverty and Inequality Platform (2024), World Inequality Database (WID.world) (2024), Luxembourg Income Study (2024): Income Across Distribution Comparison;
4. UNDP, Human Development Report (2024): Human Development Index;
5. UN WPP (2022), HMD (2023), Zijdeman et al. (2015), Riley (2005), Bolt and van Zanden - Maddison Project Database 2023: Life Expectancy vs. GDP per Capita.