Dear all,

I have a general question regarding the modeling of policy measures:

I am investigating expenditures of municipalities in a german state between 2009 and 2020 (N = 395, T = 11 years) by using a fixed effect panel data regression with a balanced panel. One central point of interest is the investigation of a policy measure that took place in 2015 and lasted until 2020. This is the reason why I am using a fixed effects model as I am intrested in intra-municipal changes over time especially due to this external shock (hausmann test recommended it as well).

This policy measure affected all municipalities, so there is no differentiation between a treatment and a controll group. Therefore, Difference-in-difference estimation does not apply in this setting. Since it is a before/after investigation, maybe a regression discontinuity design could be an option, but I am not familiar with this design yet...

Do you know in which way such policy measures could be modelled?

I woul be glad to hear from you!

Best regards
Niko