Difference between multi-point double-difference model and single point

Different sample data, different analysis methods and so on.

The sample data are different: the multi-point double-difference model collects data at multiple time points, and the single-point model collects data at specific time points.

The analysis methods are different: the multi-time double-difference model is to analyze the policy effect by comparing the differences between the experimental group and the control group before and after the policy implementation, while the single-time model is based on the data at a time point for statistical analysis.