World Gini coefficient ranking

London once again takes the lead with strong strength and becomes the best city in the world in 2021. New York in the United States, Paris in France, Moscow in Russia, and Tokyo in Japan ranked second to fifth respectively. The sixth to tenth cities are: Dubai in the United Arab Emirates, Singapore, Barcelona in Spain, Los Angeles in the United States and Madrid in Spain. There are two cities in mainland China on the list, Beijing (26th) and Shanghai (73rd), and Hong Kong, China, ranks 42nd in the world. As a popular country for studying abroad, five cities in Australia entered the list, namely Sydney (25th), Melbourne (37th), Brisbane (70th), Adelaide (75th) and Perth (89th). ). There are 6 Canadian cities on the list, including Toronto (13th), Vancouver (34th), Montreal (41st), Calgary (47th), Ottawa (67th), and Edmonton (76th).

Gini coefficient

The Gini coefficient (English: Gini index, Gini Coefficient) refers to a common indicator used internationally to measure the income gap of residents in a country or region. The maximum Gini coefficient is "1" and the minimum is equal to "0". The closer the Gini coefficient is to 0, the more equal the income distribution is. There is no international organization or textbook that provides the most suitable Gini coefficient standard. However, many people believe that when the Gini coefficient is less than 0.2, residents' income is too average. When it is between 0.2-0.3, it is more average. When it is between 0.3-0.4, it is more reasonable. When it is between 0.4-0.5, the gap is too large. When it is greater than 0.5, the gap is huge. The Gini index was first proposed by Italian statistician and sociologist Corrado Gini in 1912.

Popular Algorithm

Hirschman’s index for judging the degree of equality of distribution based on the Lorenz Curve. Let the area between the actual income distribution curve and the absolute equality curve of income distribution be A, and the area to the lower right of the actual income distribution curve be B. And the degree of inequality is represented by the quotient of A divided by (A+B). This value is called the Gini coefficient or the Lorenz coefficient. If A is zero, the Gini coefficient is zero, indicating perfect equality in income distribution; if B is zero, the coefficient is 1, indicating absolute inequality in income distribution. The more equal the income distribution is, the smaller the arc of the Lorenz curve is, and the smaller the Gini coefficient is. On the contrary, the more unequal the income distribution is, the larger the arc of the Lorenz curve is, the greater the Gini coefficient is. In addition, you can refer to the Pareto index (a measure of the degree of uneven income distribution). The Gini coefficient has an intuitive mathematical meaning.