PPFs shows all possible combinations of two goods that can be produces.
inside the ppf: not using resources efficiently / productively inefficient.
outside the ppf: not possible because there is not enough resources.
on the ppf : productively efficient
PPF SHIFTS:
for infrastructure like hospitals and roads
● increase in population; increase in more labour. shifts PPF outwards
● natural disaster, like an earthquake; PPF would shrink inwards.
for agricultural goods