Consider a small country in which the demand and supply curves of a
particular commodity are respectively given as:
Qd=120-20P (1)
Qs=20P (2)
where Qd is the quantity demanded, Qs the quantity supplied, and P the price.
(a) compute the equilibrium price and quantity under conditions of autarky and
the elasticity of demand (Ed ) and supply (Es ) at the point of equilibrium.
(b) Suppose now that the country decides to engage in trade for this particular
commodity and the international price Pw=1. Compute Qd , Qs, imports (M),
Ed , Es , and the changes in consumers’ surplus, producers’ surplus and in total
welfare. Discuss your answer.
(c) Lets assume that the country imposes a tariff t =1 per unit. Compute Qd , Qs ,
M, Ed , Es , and the changes in consumers’ surplus, producers’ surplus, total
welfare and in tariff revenue (TR) and compare the results with free trade case.