Hi,
I have a question about how to code the variables in the following DID equation.

Dep.Var= B1 IFRS + B2 Post + B3 Post * IFRS + Controls + e.


There are three cases that I want to present and I want to confirm if my coding is correct or not, please!

Case one:

Let’s suppose that I aim to examine the impacts of mandatory adoption of International Financial Reporting Standards (IFRS )in Country A, which mandated the adoption of the IFRS in 2005. Country A serves as the treatment group, while Country B, which follows Generally Accepted Accounting Principles (GAAP) and has no plans to adopt the IFRS, serves as the control group. The study will utilize DID model. In this model, the IFRS variable will be coded as one for firms in Country A and zero for firms in Country B. The Post variable, which is related to the fiscal period and not to individual firms, will be coded as one for all firms in both countries after 2005 and zero for all firms in both countries prior to 2005.

Does the coding is correct?

Case two:

Let’s suppose that I aim to examine the impacts of mandatory adoption of IFRS in Country A, which mandated the adoption of the IFRS in 2005. Country A serves as the treatment group while Country B, which follows its own local GAAP and plans to mandate IFRS adoption in 2007 with the option for firms to adopt IFRS prior to 2007. Firms in country B that didn’t apply IFRS voluntarily before 2007 will serve as a control group. To illustrate, IFRS variable will be coded as one for firms in Country A and zero for firms in Country B. The Post variable, which is related to the fiscal period and not to individual firms, will be coded as one for all firms in both countries after 2005 until 2006 (inclusive) and zero for all firms in both countries prior to 2005.

Does the coding is correct?

Case three:

Let’s suppose that we aim to examine the impacts of voluntary adoption of IFRS in Country A. Firms in Country A that voluntarily adopt IFRS serves as the treatment group, while firms that didn’t apply IFRS will serve as a control group. The study will utilize DID model. In this model, the IFRS variable will be coded as one for firms in Country A that adopted IFRS, and zero for firms in Country A that didn’t adopt. Post variable ???

How the Post variable will be coded??

Apologies for the long question and I truly appreciate your understanding. I am eager to receive a response. Thank you for your cooperation.