The graph below shows a production function and the subsistence level of output.
a. Does the production function exhibit increasing or decreasing marginal productivity?
b. Label a level of population at which the population is expected to grow. What is the surplus output at that population level?
c. Label a level of population at which the population is expected to decline. Why is the population declining at this point?
d. Label the population at which the economy is in long-run equilibrium. Why is this a long run equilibrium?