Does energy infrastructure spur total factor productivity (TFP) in middle-income economies? An application of a novel energy infrastructure index

•Examines middle-income nations' energy infrastructure-total productivity factor (TFP) nexus.•Constructs a novel energy infrastructure index using an unobserved component model (UCM).•Finds energy infrastructure-TFP nexus for both aggregated and disaggregated samples of middle-income economies.•Reveals a more intensified role of the energy infrastructure of upper-middle-income than the lower-middle-income countries.•Checks the robustness of the study findings using the Wavelet coherence analysis procedure. Even though there are numerous empirical investigations on energy consumption's impact on economic growth, the relationship between energy infrastructure and total factor productivity (TFP) appears to be understudied in academic literature. The present study examines the dynamic nexus between energy infrastructure and TFP for the panel data of 67 upper and middle-income countries during 1990–2019.First, we contribute to devising a comprehensive energy infrastructure index by covering qualitative and quantitative dimensions of energy resources using the unobserved-component model.Second, this study investigates the short and long-run relationship between the variables using the cross-sectional autoregressive distributed lag (CS-ARDL) approach. The investigation procedure confirms that energy infrastructure significantly and positively increases TFP in both the long and short run. In addition, diverse macroeconomic dynamics, e.g., foreign direct investment, human capital, technological advancement and trade openness, also positively influence TFP in these countries.Third, by categorizing the sample into upper-middle income and lower-middle income countries, this study finds higher coefficients of the energy infrastructure of the upper-middle-income group than the lower-middle-income economies to stimulate TFP. Furthermore, this study's results remain robust across the alternate estimation parameter, the wavelet coherence analysis technique.Finally, the study proposes some significant policy suggestions.