Edgar Costilla-Reyes, a researcher at the University of Santiago de Compostela, spent six months at the Bratislava University of Economics and Business through the National Scholarship Programme. Working with Professor Martin Lábaj, he examined a less visible aspect of Mexico’s export model: the foreign petroleum-sector production that supports manufacturing exports through international supply chains.

Mexico is a major exporter of vehicles, electronics, electrical equipment and machinery. These industries are closely connected to North American and global production networks. Gross trade statistics, however, provide limited information about the energy-related sectors activated before the final products are exported.

Looking beyond direct energy imports
Energy dependence is usually measured through domestic oil production, fuel imports or the national energy balance. Such indicators do not capture the petroleum and refining activities indirectly required by manufacturing production.

A vehicle assembled in Mexico relies on steel, plastics, chemicals, transport services and electronic components produced across several countries. Petroleum-related sectors enter these chains at multiple stages, even when the exported vehicle contains no direct petroleum component.

A growing dependence on foreign sources
The results show a major change in the origin of this petroleum-sector exposure. In 1995, foreign sources accounted for about 33 percent of the total. By 2022, their share had risen to more than 81 percent.

The expansion of manufacturing exports was the main factor behind this increase. Yet export growth does not explain the entire shift. More than one third of the cumulative rise was associated with higher foreign petroleum-sector requirements per unit of exports.

The strongest effects appear in manufacturing activities deeply integrated into global production networks, particularly motor vehicles and computer, electronic and optical products. The United States became the largest foreign source of the petroleum-sector production connected to Mexican manufacturing exports.

These findings reveal a structural change in Mexico’s export platform. Manufacturing exports expanded rapidly, while the petroleum and refining activities supporting them moved increasingly outside the country.

Research cooperation in Bratislava
The project brought together two complementary research agendas. Costilla-Reyes studies Mexico’s external constraints, energy structure and structural change. Professor Lábaj’s work focuses on industrial transformation, economic development and input–output analysis.

Their collaboration at the Department of Economic Policy made it possible to connect Mexico’s export specialization with the international production networks that sustain it. The National Scholarship Programme provided the time and institutional setting required to develop the empirical framework and produce the joint paper.

Why the findings matter
The study is still in progress, but the preliminary evidence suggests that Mexico’s manufacturing exports rely increasingly on petroleum and refining activities located abroad. This exposure is not visible in gross export figures and may increase sensitivity to oil-price movements, transport costs and supply-chain disruptions.

The results could help identify which industries are most exposed and inform future discussions on supplier development, industrial resilience and Mexico’s position within North American production networks.