The difference in Difference (DiD) is a popular method in empirical economics and has important applications in other social sciences as well. DID is a quasi-experimental design that uses panel data to estimate the effects of specific intervention or treatment (such as policy changes, new laws, social program implementation) on outcomes over time and between two population groups, those that are affected by this policy and those that are not. DiD, in general, is an appealing choice for researchers who want to design a research methodology based on controlling for confounding variables.
Applications of DiD are quite diverse, amongst are
- Impact evaluation (public policy analysis)
- Measuring the variations overtime (Time Series) and over individuals (Cross-Sectional Data)
- Focusing on the establishment of effects on a dependent variable derived from the interaction of exogenous variables given a treatment.
- Variants of the DiD method can account to deal with auto-selection bias and endogeneity problems.
- Comparing the differences between observed outcomes from partial and non-randomized samples in groups.
Although this method is highly important, few learning resources are available to instruct researchers and scientists how to properly implement and design it. There may be some resources that discuss the theoretical foundations of this method while listing a few examples of its applications. However a fully-fledged learning material for DiD that covers both theory, and guides researchers to implement this method on statistical software using real and simulated data applications are rather scarce.
At M&S Research Hub we recently launched a video library wherein our team of academic experts record offline training videos for advanced econometrics methods. This material is designed to fit researchers at different proficiency levels. They cover both theoretical and mathematical basics of the target models and their detailed application using statistical software, leaving the researcher in no further need to search for other learning resources.
A complete DiD course that takes around 158 minutes and is recorded over 7 videos are available in the library for everyone who wants to master the DID method.