Show, stating all required assumptions, that the growth rate of efficiency in any economy can be calculated as (where z = Z/L) gA = gy - agk - cgz b....

a. Show, stating all required assumptions, that the growth rate of efficiency in any

economy can be calculated as (where z = Z/L)

gA = gy - agk - cgz 

b. Show that the result in part (a) above implies that the growth rate of efficiency in

Malthusian economies over the long run is given by

gA = cgN

where c is the share of land rents in all incomes, and gN is the population growth rate.