I want to add age, gender, height and weight of the individuals as level-2 variables to the model.

[Feavainnince]

Hi,

I have a dataset where individuals are in the second level and the measurement occasions are in the first level.

I want to add age, gender, height and weight of the individuals as level-2 variables to the model.

Age - Numeric variable
Gender - Binary variable
Height - Numeric variable
Weight - Numeric variable

My question is "Should the level-2 variables always be nominal/binary variables?"

Can I add height and weight of the individuals as level 2 predictors?

Thanks in advance!
Menaka

[ChrisCharlton]

Higher level predictors can be continuous, so there is no reason that you couldn't add those variables too.