1. Differences-in-differences (DID) is a popular method in economics research to estimate causal effects.
2. However, there are several assumptions that need to be met for DID estimates to be reliable, and researchers should carefully consider these assumptions before relying on the results.
3. Researchers can use sensitivity analysis and alternative methods to test the robustness of their DID estimates and ensure that they are not biased by unobserved confounding factors.