why does random effect require random effects why random effects model is better than fixed effects model why random effects model is based on fixed effect what is the difference between a fixed and random effects model? why does the random effects hypothesis need to be uncorrelated why do random effects modeling require random effects to be uncorrelated with the input variables why is random effect compared to fixed effect why do random effects models require the random effects to be uncorrelated with the variables why is random effects model useful why is random effect better than fixed effect why is the random effect model more effective? why does random effect model require variables to be uncorrelated? how is a fixed affect model used which is more effective random effects or fixed effects? what is a random effects model and why is it important which type of variable can be uncorrelated in a random effect what is the difference between random effect and fixed effect which assumption does a random effects model hold? why are random effects models more efficient why does fixed and random effect model work