The Romer model can be described by 4 equations: Yt = AtLy,t (1) At+1 = zAtLa,t (2) Ly,t + La,t = L (3) La,t = l L (4) where Y is final output, A is ideas/knowledge, Ly is employment in production of final out- put, La is the number of researchers, and L is the population. i Explain each equation of the Romer model listed above ( 5 points) 4