Come calcolare l'indice di herfindahl?

Come calcolare l'indice di herfindahl?

Viceversa, quando l'indice si avvicina al valore uno (1) indica una concentrazione massima del potere di mercato. Nel settore A l'indice di Herfindahl è dato dalla sommatoria delle quote di mercato al quadrato (0,302+0,252+0,252+52+52+52+52) ed è pari a 0,225 (HA).

What is the highest value of a Gini coefficient?

• The coefficient ranges from 0 (or 0%) to %), with 0 representing perfect equality and 1 representing perfect inequality. Values over 1 are theoretically possible due to negative income or wealth. The Gini index is a measure of the distribution of income across a population.

What does a high Gini coefficient mean?

• If A is a very large area (making B very small), then the Gini Coefficient is large (almost 1) and it means there is very uneven distribution of income. Countries with a high Gini Coefficient are more likely to become unstable, since there is a large mass of poor people who are jealous of the small number of rich people.

How is Gini coefficient calculated?

• The Gini coefficient is calculated as the area A [between the curve and the line of equality] divided by the sum of areas A and B [everything under the line of equality]. If income is distributed completely equally, then the Lorenz curve and the line of total equality are merged and the Gini coefficient is zero.

What are the limitations of Gini coefficient?

• Sample bias. The validity of Gini coefficient calculations can be dependent on the size of a sample. ...
• Data inaccuracy. The Gini coefficient is prone to systematic and random data errors. ...
• Same Gini coefficient but different income distribution. ...
• Does not reflect the structural changes in a population. ...