Journal of Comments and Replications in Economics

Alfani and Carballo (2023) estimate income inequality in the Aztec Empire around 1492. Their
preferred estimate gives a Gini index of 50.4. They conclude that inequality was high even before
the Spanish conquest. First, I confirm that the main outcomes are computationally reproducible
from the analysis data provided in the replication package. Second, I examine two inconsistencies.
Third, I test the robustness reproducibility of the relationship between population density and
per capita income through eight different robustness tests, confirming a positive and statistically
significant relationship but with considerable variation in the point estimates. Finally, I use
these estimates as inputs for robustness measures of the main outcomes. The results support the
qualitative conclusion that inequality and extraction were substantial before the Spanish conquest.
Their exact magnitudes, however, depend on modelling choices and should be interpreted as
approximate historical estimates rather than precise measurements.