Displayingthe characteristic that models derived from inter-individual studies areasymptotically identical to those derived from the same models at anintra-individual level. In essence, a process where cross-sectional,longitudinal, and time-series models will all show the same results. Astochastic Gaussian model, like most GLM-based models, will meet the criteriafor ergodicity if it is acyclic and stationary, such that its mean and laggedautocorrelation structure do not change over time.
See Stationarity, Time-series