As mentioned previously, the relationship between the government budget deficit and current account deficit is
a matter concentrated by policymakers and researchers during past two decades, and a lot of theoretical and
empirical studies have been done accordingly. So countries faced with current account deficit try to apply
policies led to decrease mentioned deficit or remove it. The debate among economists about this matter has
mainly focused on two major theoretical models.
The first one is the Keynesian notion which considers the change of government budget as the main factor of
economic variables changes, specially the foreign sector of the economy. While every tax reduction or
government expenditure lift causes increasing the aggregate expenditure of the economy and uprising the
inflation and interest rates. This raise of interest rate results in crowding out effect in domestic economy and
also in the capital inflow to the country. This reaches the raise of foreign exchange supply resources in the
domestic market of exchange and the raise of domestic demand towards import of foreign products because of
affecting on exchange rate, also this leads to decrease demand of foreigners for the domestic products.
Furthermore, the raise of the rate of inflation caused by implementation of expansionary fiscal policy results in
increasing the relative value of domestic against foreign goods and increasing the current account deficit in the
economy. Based on above, many researches like Normandin(1999), Vamvoukas(1999), Hashemzadeh and
Wilson(2006), Neaime(2008) and Nawaz Hakro(2009) by applying statistical techniques have offered reliable
evidence about confirmation of the Keynesian’s theory and acceptation of twin deficit hypothesis.
On the other hand, another opinion about the relationship between the government budget deficit and current
account deficit relates Ricardian equivalence hypothesis which shows that the taxes and government
expenditures don’t affect economic variables especially current account deficit. This hypothesis that is more
debatable among economists but is less noticeable than previous notion demonstrates; one unit reduction in
government tax revenue equivalent to reduction in public saving and this means one unit raise in private sector
saving. In fact because no change appears in national saving, the real interest rate evaluated by making balance
between national saving and investment will not be increased and this issue will not affect investment (Barro
(1989)).
In other words, applying government fiscal policy or any reduction or increase of tax or government expenditure
and also budget deficit doesn’t affect the real interest rate or current account and investment. Some researchers
as Enders and Lee (1990), Evans and Hasan (1994) and Kaufmann, Winckler and Scharler (2002) confirm this
view by applying empirical tests.
3. THEORETICAL MODEL
To illustrate the relationship between the government’s fiscal policy and foreign current account balance, by
using Keynesian aggregate demand and supply model for a small open-economy country, we construct a model
for comparing twin deficit hypothesis (TDH) against Ricardian equivalence hypothesis (REH).
Consider national income equation as below:
Y C I G NX
(1)
Where Y stand for gross domestic product or aggregate demand, C for private consumption, I for gross
investment expenditure, G for government expenditure and NX for net export.
On the other hand, aggregate supply is:
Y C S T
(2)
Where S is private saving and T is taxes or mandatory s