Energy Intensity and Economic Complexity: Why National Income Changes the Story

Researchers examined the relationship between energy intensity and the sophistication of national production. Their analysis considered human capital, globalization and economic freedom, dividing countries into four income groups to examine different development settings.

Building a more advanced economy takes more than opening factories or increasing exports, because the knowledge, technology and energy behind production matter just as much. A country's ability to make sophisticated products depends on the skills of its workers, the reliability of its infrastructure and the capabilities of its businesses. The energy needed to support those activities raises a practical question about how industrial development can fit with a more sustainable future.

The study "The Energy Footprint of Economic Complexity: How Does Energy Intensity Shape the Global Production Matrix?", published in Sustainability, explores that question using evidence from 135 countries between 2000 and 2022. Researchers Marcelo Leon, Maria de la O Barroso Gonzalez and Bryan Rivera examined the relationship between energy intensity and the sophistication of national production. Their analysis considered human capital, globalization and economic freedom, dividing countries into four income groups to examine different development settings.

The findings offer no simple formula linking lower energy use with a more advanced economy, and several passages in the paper conflict with its reported results. The regression table shows a positive relationship between energy intensity and economic complexity in the two higher-income groups, despite passages describing the relationship in the opposite direction. A careful reading separates those numerical findings from the authors' broader recommendations about energy efficiency and industrial development.

What Energy Use Reveals About an Economy

Energy intensity measures the amount of energy needed to produce one unit of economic output, rather than the total energy a country consumes. A lower figure means less energy is used relative to output, though the industries making up an economy can influence that figure. Economic complexity describes the productive knowledge reflected in the diversity and sophistication of the goods a country can competitively produce or export.

The researchers drew on sources including Harvard's Growth Lab, the World Bank, the Heritage Foundation, the United Nations Development Programme and the KOF Swiss Economic Institute. Their fixed-effects analysis examined changes within countries, accounting for persistent national characteristics and including human capital, globalization and economic freedom. Separate Granger tests checked whether earlier energy-intensity values helped predict economic complexity, or whether earlier complexity values helped predict energy intensity.

The descriptive averages show richer countries combining greater economic complexity with lower energy intensity, alongside higher values for the three supporting indicators. Average complexity ranged from 0.90 in high-income economies to −0.98 in low-income economies, with average energy intensity rising from 4.72 to 8.23 across those groups. These comparisons describe differences between groups, so they cannot replace the analysis of changes within individual countries.

Why the Findings Change Across Income Groups

The regression table reports positive energy-intensity coefficients of 0.0597 for high-income countries and 0.0393 for upper-middle-income countries, with stronger evidence for these relationships than for those in poorer groups. Those estimates associate increases in the measured energy-intensity variable with increases in economic complexity after accounting for the other included factors. The authors suggest that sophisticated manufacturing and interconnected supply chains can still require substantial energy, without establishing that energy inefficiency helps an economy develop.

The estimates for lower-middle-income and low-income countries were too uncertain to establish a clear relationship between energy intensity and complexity. Globalization had a supported positive association in high-income countries, with no equally clear finding for the remaining groups. Human capital and economic freedom showed no clear independent associations at the paper's usual threshold, which does not mean education, skills or institutions are unimportant.

The models captured only a small share of changes in economic complexity, with adjusted explanatory values of roughly 13%, 6% and 4% across the first three income groups. The low-income model had virtually no explanatory power after adjustment, leaving substantial room for factors missing from the analysis. Infrastructure, technology access, industrial specialization and institutional capacity are possible explanations discussed by the authors, rather than mechanisms demonstrated by these results.

Energy Patterns Can Predict Change Without Proving Its Cause

The reported Granger tests found that earlier energy-intensity values helped predict economic complexity in high-income, lower-middle-income and low-income countries. Neither direction received support in the upper-middle-income group, and no group showed supported prediction running from economic complexity to energy intensity. These findings concern information contained in past values, rather than proof that changing energy policy will directly change what a country produces.

The distinction helps explain how poorer groups could show predictive relationships without clear relationships in the regression analysis. Each method asks a different question, separating changes observed together from patterns that help forecast later outcomes. The absence of reverse prediction cannot rule out every possible influence of economic complexity on energy use, and formal comparisons would be needed to establish differences between groups.

The paper's internal inconsistencies make its strongest claims difficult to accept without clarification, particularly the passages describing lower energy intensity as beneficial despite positive regression coefficients. National averages conceal differences between industries, and the analysis does not separate renewable energy from fossil fuels or directly test specific technologies. The authors identify sector-level data, energy sources, innovation, institutional quality and nonlinear relationships as priorities for future research.

What Sustainable Industrial Development Could Look Like

For high-income and upper-middle-income economies, the authors recommend connecting energy efficiency with industrial modernization, innovation and higher-value production. Practical priorities include upgrading production equipment, adopting energy-saving technologies and strengthening businesses' ability to use advanced knowledge. These recommendations reflect the authors' interpretation of the evidence, rather than measured results from policy interventions.

Lower-middle-income and low-income countries may need to strengthen the foundations that allow businesses to expand into more sophisticated activities. Reliable energy access, education, productive infrastructure, technology adoption and institutional capacity form the proposed package, with efficiency built into industrial development. The lack of clear regression findings gives no basis for assuming that an isolated improvement in any single indicator will automatically transform production.

Expanding production can increase energy demand and resource use. This study examines energy intensity and productive sophistication, without directly measuring reductions in carbon emissions or environmental damage. Its practical message is to design energy and industrial policies around countries' capabilities, supported by clearer evidence about the technologies and industries driving change.