<p>Relevant structural analysis.</p>

The empirical results show that policy preferences play a significant mediating role between institutional frameworks and energy cooperation outcomes. Specifically, the Bayesian SEM estimates a positive indirect effect of 0.305, with a standard error of 0.123, a 95% confidence interval of (0.061, 0.552), and a significance level of p = 0.006. This indicates that institutional arrangements promote energy cooperation mainly by shaping policy preferences rather than through direct effects alone.

Compared with classical regression-based mediation, classical SEM, Bayesian regression, and other alternative approaches, Bayesian SEM demonstrates stronger performance in handling latent-variable uncertainty, interval estimation, and parameter stability. Across the 12 estimation methods employed in this study, the estimated indirect effects range from 0.271 to 0.312 and remain consistently significant, confirming the robustness of the mediation mechanism.

This indicates that while maintaining directional consistency, it offers more robust and reliable handling of latent variables and uncertainty.</p></div>