However, because of the repeated observation at the individual level, they have more power than cross-sectional observational studies, by virtue of being able to exclude time-invariant unobserved individual differences and also of observing the temporal order of events.
然而，由于在个体层面上反复观察，它们比横断面观察研究具有更大的效力，因为它能够排除非时变的未观察到的个体差异，也能够观察事件的时间顺序。