Fig. 3
From: Applications of structural equation modeling (SEM) in ecological studies: an updated review
Illustration of a hierarchical SEM. This measurement model has observed variables (y1, y2, y3) with three hierarchies (g1, g2, g3), which specify the causal effects (i.e., Cluster 1 → Cluster 2 → Cluster 3) among the three hierarchies (modified from Rabe-Hesketh et al. 2012)