Evaluating the Additionality and Development Impact of Blended Finance in Latin American - Energy Sector: A Quasi-Experimental Approach

Purpose: This study evaluates the financial and developmental additionality of blended finance in Latin America’s energy sector. It asks whether concessional capital mobilizes private investment beyond what would occur otherwise, and whether it generates measurable climate benefits. Originality: Despite the scale of blended finance, rigorous evidence remains scarce. Most assessments emphasize headline leverage ratios without counterfactuals and rarely consider development outcomes. By using verified project-level data and quasi-experimental methods, this study addresses these empirical gaps and provides causal insights into both financial and developmental effectiveness. Methodology: A dual evaluation design is applied. Financial additionality is assessed among 296 energy PPPs using Inverse Probability Weighting (IPW), which reweights controls to mitigate selection bias and establishes fully private PPPs as the most stringent counterfactual benchmark. Developmental additionality is estimated through cross-sectional regression on CO2 reduction efficiency across 39 IDB-supported projects with project-level controls. While a formal Difference- in-Differences design was infeasible due to data constraints, the cross-sectional approach remains valid as the outcome captures ex post reductions relative to baseline, reinforced by robustness checks including a renewables-only test. Result: Blended-financed projects mobilized less private capital than fully private PPPs, reflecting their concentration in commercially marginal contexts with weaker institutions, shallower financial markets, and riskier subsectors. This pattern suggests that concessional resources are deliberately allocated to projects unlikely to proceed on commercial terms, rather than displacing existing private flows. At the same time, blended-financed projects achieved nearly nine times higher CO2 abatement efficiency than ODA-only projects, demonstrating substantial developmental additionality. Conclusions and Implication: The findings highlight that mobilization ratios alone may misrepresent financial additionality and must be complemented by outcome- based metrics. For policymakers, this implies redefining evaluation success criteria toward counterfactual and outcome-oriented measures, targeting frontier markets where concessional resources yield the greatest impact, and strengthening data systems for systematic reporting of environmental and social outcomes.