He is most noted for his work on dependency theory, the political economy of development in Latin America, and income distribution.
[1][2] He is also known for the Palma ratio, which is defined as the ratio of the richest 10% of the population's share of gross national income divided by the poorest 40%'s share.
This is based on Palma's finding that middle-class incomes almost always represent about half of gross national income.
In contrast, the other half is split between the richest 10% and the poorest 40%, but the share of those two groups varies considerably across countries.
[3][4][5][6] Palma gave the 2020 Amartya Sen Lecture, for the Human Development and Capability Association (HDCA) Conference on What Went Wrong With European Social Democracy: On Building a Debilitating Capitalism, Where Even the Welfare State Subsidises Greater Market Inequality.