CausalImpact estimates an intervention’s effect by comparing observed post-event outcomes with a model-based counterfactual prediction of what would have happened without the event. section 11.3.6
The result reports:
- Actual and predicted values for the selected post-treatment period. section 11.3.6
- Absolute and relative effects, with average and cumulative summaries. section 11.3.6
- Confidence intervals and plots showing pointwise and accumulated differences. section 11.3.6
R analysis
Choose pre- and post-treatment periods, then run `CausalImpact(df, pre.period, post.period)`. Evaluating the complete post-event period estimates an absolute effect of 443, with a confidence interval of 197 to 700 in the synthetic example. section 11.3.6
