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By the end of this section, you will be able to:

  • Explain the national saving and investment identity in terms of demand and supply
  • Evaluate the role of budget surpluses and trade surpluses in national saving and investment identity

When governments are borrowers in financial markets, there are three possible sources for the funds from a macroeconomic point of view: (1) households might save more; (2) private firms might borrow less; and (3) the additional funds for government borrowing might come from outside the country, from foreign financial investors. Let’s begin with a review of why one of these three options must occur, and then explore how interest rates and exchange rates adjust to these connections.

The national saving and investment identity

The national saving and investment identity, first introduced in The International Trade and Capital Flows chapter, provides a framework for showing the relationships between the sources of demand and supply in financial capital markets . The identity begins with a statement that must always hold true: the quantity of financial capital    supplied in the market must equal the quantity of financial capital demanded.

The U.S. economy has two main sources for financial capital: private savings from inside the U.S. economy and public savings.

Total savings = Private savings (S) + Public savings (T – G)

These include the inflow of foreign financial capital from abroad. The inflow of savings from abroad is, by definition, equal to the trade deficit, as explained in The International Trade and Capital Flows chapter. So this inflow of foreign investment capital can be written as imports (M) minus exports (X). There are also two main sources of demand for financial capital: private sector investment (I) and government borrowing. Government borrowing in any given year is equal to the budget deficit, and can be written as the difference between government spending (G) and net taxes (T). Let’s call this equation 1.

Quantity supplied of financial capital  =  Quantity demanded of financial capital Private savings + Inflow of foreign savings  =  Private investment + Government budget deficit S + (M – X)  =  I + (G –T)

Governments often spend more than they receive in taxes and, therefore, public savings (T – G) is negative. This causes a need to borrow money in the amount of (G – T) instead of adding to the nation’s savings. If this is the case, governments can be viewed as demanders of financial capital instead of suppliers. So, in algebraic terms, the national savings and investment identity can be rewritten like this:

Private investment  =  Private savings  +   Public savings   +  Trade deficit I  =  S + (T – G) + (M – X)

Let’s call this equation 2. A change in any part of the national saving and investment identity must be accompanied by offsetting changes in at least one other part of the equation because the equality of quantity supplied and quantity demanded is always assumed to hold. If the government budget deficit changes, then either private saving or investment or the trade balance—or some combination of the three—must change as well. [link] shows the possible effects.

Questions & Answers

which model predicted a global collapse in the world's social and economic system before the year 2010
Francis Reply
what is the formula of mixed income ?
Sanjum Reply
labor force in.Nigeria is seen as .......?
Aisha Reply
Is demand the same as being in need of a product?
Aphiwe Reply
Demand is defer from only need of products
need is the primary and main root of demand. but demand is the result of combination of need; income capacity and desire to expend of money for that product.
products or services
what is price determination?
Alick Reply
why are imports subtructed when GDP is calculated in the expenditure approach
what is fiscalpolicy
nati Reply
The way of the government expenses and other analysis
It explains government spending and how it helps to direct the economy towards the desired direction. For instance, if the govt of a nation is desirous of achieving economic growth and development, then the govt will adopt an expansionary fiscal policy which imply more spending by the govt.
and politics party important
mujtaba Reply
politics party important
Which party is that
persons who stopped searching for jobs but would accept if the opportunity presents itself
Torissa Reply
persons who are unemployed whether they are underage, retired or incapacitated
the us economy is best characterized as?
what is the impact of fiscal policy in the short and long run in the AD/AS model...
Hydrammeh Reply
What is demand
Mohd Reply
Demand is the desire for a commodity backed by the willingness and the purchasing power too.
what is the impact of the higher tax rate on the business and the economy at large..?
Hydrammeh Reply
aggregate demand decreases and GDP decreases in the long run prices will decrease because aggregate supply will shift to the right and increase
Thanks, Murabit
But still I will need more explanation
no problem tax rate is a form of fiscal policy so any time the government changes spending or taxes it will directly affect the economy
but remember that there at different economic views on fiscal policy there is classical,Keynesian and moneterism
if taxes increase aggregate demand decreases causing a fall in prices causing a fall in the money demand lowering interest rate and increasing investment spending in turn increasing prices
thanks so much Murabit
what are the policy recommendations for impact of government borrowing?
Baisiro Reply
how can I get Utility notes here
Tabea Reply
I also want to know
I have them
money and money supply
Yogesh Reply
money is anything that is generally accepted as payment of goods and services or that is accepted in settlement of debt.
Money supply?
Money supply is the total value of monetary assets available in an economy at a specific time.
supply of money:- The total quantity of money in an economy at a point of time......
What is the difference between monetary economy and barter economy?
monetary economy is simply an economy where money acts as a medium of exchange and barter economy is why where goods acts as a medium of exchange
Thank you Ittoo.
please cut why.....in last ans
and no need of thanks dear
Don't damend work in inflation
Mishael Reply

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Source:  OpenStax, Macroeconomics. OpenStax CNX. Jun 16, 2014 Download for free at http://legacy.cnx.org/content/col11626/1.10
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