Public interest and scholarly output on renewable energy and the shadow economy: Evidence from Google Trends and academic databases

Understanding the alignment between public interest and academic research is increasingly relevant in the context of global sustainability challenges. This study aims to investigate the relationship between societal attention, as measured by Google Trends, and scholarly output on renewable energy and the shadow economy. Using bibliometric data from Scopus and Web of Science alongside global Google Trends data from 2004 to 2025, the analysis employed Pearson and Spearman correlation coefficients, Granger causality, and distance correlation to assess the strength, direction, and form of association between public search trends and academic activity. The results reveal a significant Granger-causal relationship from public searches on “renewable energy” to academic publications, with F-statistics above 5.2 (p < 0.01), and strong positive correlations (Pearson r = 0.72; Spearman ρ = 0.69; distance correlation = 0.63). In contrast, the terms “informal economy” and “feed-in tariff” demonstrated weak or inconsistent associations, with correlations below 0.25 and statistically insignificant causality tests (p > 0.1). Cross-country comparisons further highlighted uneven alignment, with India showing high search intensity (Google Trends index > 75) but relatively low publication volume (< 2% of global output). At the same time, South Africa displayed closer coherence, with both indicators moving in tandem (r ≈ 0.61). These findings underscore scholarly research’s partial and asymmetric responsiveness to public demand, varying significantly by topic and geographic context. Moreover, while Google Trends offers robust signals of societal interest, disparities in digital access and literacy reduce its universality, pointing to critical underexplored research gaps with direct policy relevance.