TY  - RPRT
        AU  - Stark, Oded
AU  - Kosiorowski, Grzegorz
        TI  - A Demarcation of the Gini Coefficient
        PY  - 2025/Jul/
        PB  - Institute of Labor Economics (IZA)
        CY  - Bonn
        T2  - IZA Discussion Paper
        IS  - 18045
        UR  - https://www.iza.org/index.php/publications/dp18045
        AB  - We specify the domain in the income distribution that includes the people to whom income transfers will not increase inequality in that income distribution. Inspired by Sen’s (1973, 1997) characterization of the Gini coefficient as a ratio between a measure of aggregate income-based “depression” (stress) and aggregate income, we inquire as to whether in the wake of an increase of an income or of incomes in a given income distribution, the Gini coefficient does not increase. To this end, we identify the corresponding “safe” domain and show that the pivotal value that demarcates this domain can be elicited from a simple linear function of the Gini coefficient itself. Our rule of demarcation provides for policy interventions that seek to increase a particular income or particular incomes while not exacerbating inequality in the income distribution as measured by the Gini coefficient.
        KW  - Gini coefficient
KW  - aggregate income-based stress
KW  - aggregate income
KW  - rank-preserving increase of an income or incomes
KW  - pivotal value
KW  - sufficient condition for the Gini coefficient not to increase
        ER  -