how is the hdi measured 
the hdi is a summary measurement of basic achievement levels in human development the computed hdi of a country is an average of indexes of each of the life aspects that are examined knowledge and understanding a long and healthy life and an acceptable standard of living each of the components is normalized to a scale between zero and one and then the geometric mean of the three components is calculated 2the final hdi score for each country is calculated as a geometric mean of the three components by taking the cube root of the product of the normalized component scores 2switzerland scores the highest among 193 countries in the 2023 2024 hdi rankings from the u n 4hdi rankingstop hdi scores go heavily to northern european countries while the lowest scoring nations are largely found on the african continent the top 25 countries in the 2023 2024 hdi rankings are in the table below 4the bottom five countries are in the table below 4limitations of the hdithere are criticisms of the hdi it is a simplification and an admittedly limited evaluation of human development the hdi does not specifically reflect quality of life factors such as empowerment movements or overall feelings of security in recognition of these facts the u n human development report office hdro provides additional composite indices to evaluate other life aspects including inequality issues such as gender disparity or racial inequality examination and evaluation of a country s hdi are best done in concert with examining these and other factors such as the country s rate of economic growth expansion of employment opportunities and the success of initiatives undertaken to improve the overall quality of life within a country several economists say the hdi is essentially redundant as a result of the high correlations among the hdi its components and simpler measures of income per capita gni per capita or even gdp per capita correlates very highly with both the overall hdi and the other two components in both values and rankings 5given these strong and consistent correlations they say it would be simpler and clearer just to compare per capita gni across countries than to spend time and resources collecting data for the additional components that provide little or no additional information for the overall index 5indeed a fundamental principle of the composite index design is to not include multiple additional components that are strongly correlated in a way that suggests that they might reflect the same underlying phenomenon this is to prevent inefficient double counting and avoid introducing additional sources of potential errors in the data in the case of the hdi the inclusion of the components is problematic because it is easily plausible that higher average incomes directly lead to both more investment in formal education and better health and longevity moreover definitions and measurements of years of schooling and life expectancy can vary widely from country to country 