Today I read a discussion and I saw a phrase "inter-temporal evolution".
A pre-trend analysis isn't a requirement, though it improves the credibility of a study. Typically, evaluators plot the outcome trends for the treatment group and the control group over time. We should expect the inter-temporal evolution of the trends to be reasonably parallel before the law/policy is enacted.
For example, the authors in the paper you referenced plot the mean change in >asset growth in both groups in the 2 years before and the 5 years after the >adoption of a leniency law.
I am wondering what does it mean in this situation.