Inequality in manufacturing income distribution in Guanajuato and Nuevo León: a comparative analysis using Lorenz curve, Gini coefficient and geographic information systems

Abstract

This presents a comparative analysis of income inequality resulting from the supply of goods and services in the manufacturing industry in the states of Guanajuato and Nuevo León, Mexico, two of the country's main manufacturing hubs. To do this, the Lorenz curve, the Gini coefficient, and geospatial representations in QGIS are used. Using data from the INEGI Economic Censuses, in Guanajuato (46 municipalities) and Nuevo León (52 municipalities), Gini coefficients of 0.78 and 0.75 were calculated, respectively, indicating critical levels of manufacturing income concentration at the municipal level. The Lorenz curve equation for Nuevo León is y = 0.0187x² − 1.3136x + 12.394, and for Guanajuato, y = 0.0183x² − 1.3412x + 12.611. Both show strong concavity and diverge from the line of perfect equality. In Guanajuato, municipalities in the Sierra Gorda have income distribution percentages below 0.002%, while in cities like León, Celaya, Silao, Irapuato, and Salamanca, the percentages range between 7.05% and 31.30%. In Nuevo León, the Monterrey metropolitan area (including Monterrey, Apodaca, San Nicolás de los Garza, Santa Catarina, and Pesquería) accounts for the highest incomes, ranging from 7.56% to 25.65%, while municipalities in the Sierra Madre Oriental show marginal percentages. The results suggest that both economies, although dynamic, maintain highly unequal manufacturing distribution structures, which have significant implications for the design of public policies on productive decentralization and balanced territorial development.