Estimating income inequality using single-parameter Lorenz curves: a new proposal

In a recent paper, Paul and Shankar (2020) introduced a single-parameter Lorenz curve that provides an improved fit compared to many existing uniparametric models. This paper explores new properties of their model, offering a refined representation in terms of convex linear combinations of Lorenz cu...

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Detalles Bibliográficos
Autores: Sarabia Alegría, José María|||0000-0002-9619-4721, Jordá, Vanesa, Tejería Martínez, Mercedes
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/37907
Acceso en línea:https://hdl.handle.net/10902/37907
Access Level:acceso abierto
Palabra clave:Gini index
Functional form
Lorenz ordering
Inequality
Descripción
Sumario:In a recent paper, Paul and Shankar (2020) introduced a single-parameter Lorenz curve that provides an improved fit compared to many existing uniparametric models. This paper explores new properties of their model, offering a refined representation in terms of convex linear combinations of Lorenz curves. We also derive closed-form expressions for several inequality measures and examine the Lorenz ordering. However, we identify a key limitation: The Gini index for this curve is lower bounded at 0.418, making the model unsuitable for income distributions with lower inequality. To address this issue, we propose an alternative model that extends the range of the Gini index, allowing for greater flexibility in representing income distributions across a wider range of inequality levels. Our results suggest that the Lorenz curve proposed in this paper surpasses the proposal by Paul and Shankar, even in countries with high inequality, where the constraint imposed by the Gini index is not binding.