We study the problem of identifiability of the total effect of an intervention from observational time series only given an abstraction of the causal graph of the system. Specifically, we consider two types of abstractions: the extended summary causal graph which conflates all lagged causal relations but distinguishes between lagged and instantaneous relations; and the summary causal graph which does not give any indication about the lag between causal relations. We show that the total effect is always identifiable in extended summary causal graphs and we provide necessary and sufficient graphical conditions for identifiability in summary causal graphs. Furthermore, we provide adjustment sets allowing to estimate the total effect whenever it is identifiable.

翻译：我们研究了仅基于观测时间序列的系统因果图抽象时，干预总效应的可辨识性问题。具体考虑两类抽象：一类是扩展摘要因果图，该图合并了所有滞后因果关系，但区分了滞后关系与即时关系；另一类是摘要因果图，该图未对因果关系间的时滞提供任何指示。我们证明总效应在扩展摘要因果图中始终可辨识，并给出了摘要因果图中可辨识性的必要与充分图论条件。此外，我们提供了调整集，使得在总效应可辨识的情况下能够估计该效应。