I'm trying build a model to predict sells of clothe store for each cluster to month 11 and 12.
I've 98 stores, and for each store i have this data, but i put the all data to calc only 1 model.
I use R to calc the model, and i have this "Coefficients: (1 not defined because of singularities)" the coefficent is S11. i've already read that it happens because there is correlation between the variables, but i dont know how fix it or if my model is correctly created.
thank you so much!
competition is the level on competition where the store are located (1= low 2=medium 3 = high)
Cluster = 1,2,3,4,5 depends which cluster the store belongs.
S01, S02, S03 ....S11 is the dummies for sazonality. Year, 1= 2015 and 2=2016 Obs= Observation number