Portuguese 
Spanish 
Study Led by Adam S. Green in PNAS Uses the Archaeological Collection of the GINI Project to Show That Extensive Exchange Networks First Increase Productivity and Then Concentrate Wealth, Challenging Kuznets’ Classic Optimism.
Simon Kuznets’ thesis (1955) argued that economic development raises inequality only in the early stages, as subsequent prosperity would reduce it.
Decades of modern data have shown that the proposed “arc” does not always materialize; economies grow while maintaining or even increasing income concentration.
To test the idea on larger scales, Green joined the GINI project, which collects measures of excavated homes worldwide as a proxy for wealth.
-
She spent 73 years breathing inside an iron lung, survived the aftereffects of polio, and became the last woman in the United States dependent on the equipment before dying at 78 years old.
-
Brazilian students created a $1 filter using pine bark, cotton, and 3D-printed parts to clean cassava wastewater, reduce the toxicity of a hazardous waste, and transform contaminated water into biofertilizer.
-
Astronaut from Artemis II steps down after mission to the Moon and decision surprises after a record of 406,771 km, a historic 10-day journey, and an unprecedented achievement for Canada.
-
A fossil kept for years in a small museum in Montreal concealed 450-million-year-old soft tissue, a discovery that has only happened once before in history.
The database includes 53,464 residences distributed across 1,176 sites from 21,000 B.C. to the present, allowing the estimation of productivity (average area) and inequality (Gini coefficient) over long intervals.
Applying economic tools to material evidence gives researchers an impossible temporal scope for conventional historical series.
The central objective: to discover whether the cycles of growth and equality observed by Kuznets repeat, or not, when analyzing millennia of “old-fashioned” globalization.
How “Kuznets Tides” Arise in Three Super Trade Networks of the Past
The authors focused on areas where exchange traversed continental distances for their times, forming almost global “worlds.”
In the Bronze Age Interaction Zone (West and South Asia, 3rd-2nd millennium B.C.), the expansion of standard weights and caravan routes coincides with an initial decline in inequality and a jump in average house area.
A similar phenomenon appears in the Mayans’ World, where cities connected by long exchange systems first experienced diffuse prosperity, then power accumulation among classical elites.
Pre-Roman Britain experienced productive gains and greater wealth balance with Atlantic trade; under the Roman Empire, aristocratic land holdings abruptly raised the Gini.
These repeated peaks and valleys, labeled “Kuznets’ Tides,” suggest that initially inclusive market rules can be captured by elites and reversed into wealth extraction.
The cyclical pattern contradicts Kuznets’ expectation of permanent convergence: the tide rises for everyone, but then drops for many while continuing to rise for a few.
Lessons for Sustainable Development in the 21st Century
Global trade is not exclusive to modernity; its social consequences follow logics that already manifested millennia ago.
Phases of growth with low inequality coincide with more open market governance, standardization of weights, currencies, and contracts accessible to multiple groups.
When restricted groups control these same institutions, “high tides” of concentration emerge that, according to the study, end up suffocating overall productivity.
Green and colleagues argue that current globalization policies can learn from these archaeological metrics: maintaining plural rules and oversight against monopolies is central to avoid the tide effect.
The research provides a large-scale empirical framework for debates on trade-offs between growth and equity in trade protocols such as the WTO, regional agreements, and global supply chains.
Authors’ conclusion: “Over time, increasing inequality often turns the tide against growth, ending cycles of sustainable development.”
