neoclassical growth

CFA Level II Economics
#1

I think I understand neoclassical growth theory but I don’t think I understand how to apply it using the formulas show below:

sustainable g rate= total factor productivity g rate / labor cost as a percentage of total factor cost + growth in labor

  1. what is the interpretation of ‘labor cost as a percentage of total factor cost’

and 2) I understand that the sust g rate would be higher if total factor productivity was higher or if growth in labor was higher, but why is it higher if the labor cost as a percentage of total factor cost’ is low?

  1. why isn’t the ‘capital cost as a percentage of total factor cost’ also involved in this formula- aka we only look at the labor cost??

thanks!