National-level modeling

Meridian supports national-level models, although we recommend that you use the geo-level model when possible. The national-level model is a special case of the geo-level model with only a single geo. There is no separate model class.

The following parameter restrictions apply, and are automatically enforced, when you use the national-level model:

• \(\eta^{[M]}_i=0\) and \(\beta_{1,i}^{[M]}=\beta_i^{[M]} \ \ \forall i\)
• \(\eta^{[OM]}_i=0\) and \(\beta_{1,i}^{[OM]}=\beta_i^{[OM]} \ \ \forall i\)
• \(\eta^{[RF]}_i=0 \) and \(\beta^{[RF]}_{g,i}=\beta^{[RF]}_i \ \ \forall i\)
• \(\eta^{[ORF]}_i=0 \) and \(\beta^{[ORF]}_{g,i}=\beta^{[ORF]}_i \ \ \forall i\)
• \(\xi_i^{[C]}=0\) and \(\gamma_{1,i}^{[C]}=\gamma_i^{[C]} \ \ \forall c\)
• unique_sigma_for_each_geo = False

Note: Population scaling has no effect in the national-level model.