Week 9 – SS2 Third Term Economics Notes

WEEK NINE
THEORY OF INCOME DETERMINATION
CONTENT

1. Circular Flow of Income
2. Concept of Saving
3. Concept of Investment
4. Concept of Consumption

    CIRCULAR FLOW OF INCOME
   Circular flow of income shows the independence or relationship between households and business enterprise
               Supply of Goods and Service

    
                Payment for goods and services                
   

    
           

    
    
            
   

                Wages, Interest, Rent and Profits
   

    
    
    
                Productive Services or Resources
   

    Commodity and money flows between households and firms. It shows the flow of payments from business sector to households in exchange for labour and other productive services and the return flow of payments from households to business sector in exchange for goods and services.

    The household or the personal sector offers its labour services to the business sector or firms in the production of goods and services. The household is rewarded in form of wages, interest and rent which it spends on the consumption of goods and services produced in the economy.

    FACTORS THAT BRINGS ABOUT CHANGES IN THE CIRCULAR FLOW OF INCOME
   1.    Withdrawal: This part of all the income that is not all owed to pass through the normal channel of circular flow of income.
   2.    Injection: This forms an increase in the income of households, producers outside their normal processes of selling productive resources and manufactured goods.
   3.    Savings: These are part of income which are not consumed immediately and they reduce households and producers expenditures.
   4.    Investment: This reduces and creates additional income either immediately or in future.
   5.    Gifts and grants: They may come from governments to households and firms and help increasing their incomes
   6.    Taxes: They reduce the expenditures of households and firms on goods and factor services.
   7.    Imports: They involve expenditure on foreign made goods and services and constitute withdrawals from the circular flow of income.
   8.    Export: They Provide money from other countries and act as injection into the domestic circular flow of income.

    EVALUATION
   1.    Explain the following terms:
       i. Withdrawal    ii. Savings    iii. Injection.    Iv. Import and Export

    CONCEPTS OF SAVINGS, INVESTMENT AND CONSUMPTION
   SAVINGS
   Savings are made up of disposable income which is not spent on consumer goods and services. Saving involves forgoing some present consumption.

    Individuals save for the following reasons:
   1.    To raise capital
   2.    For unforeseen contingencies
   3.    For speculation
   4.    To acquire assets
   5.    For future purposes
   6.    To raise social status

    Factors that affect savings
   

   1. The size of income
   2. The rate of interest
   3. Cultural attitude
   4. Government polices
   5. Availability of financial institutions.

    EVALUATION
   1. Give four reasons why individual saves.
   2. List and discuss three factors affecting savings.

    INVESTMENTS
   Investment may be defined as expenditure on physical assets which are not for immediate consumption but for production of consumer and capital goods and services.
   Types of Investment
   1.    Individual investment: This may be on building, motor vehicles and other assets the individual hopes may increase his income and standard of living.
   2.    Investment by firms: This can be on buildings machines, furniture, raw materials, semi finished and finished goods.
   3.    Government investment in social capital; These are in the areas of roads, electricity, pipe borne water, hospitals schools.
   Purpose: to improve the living condition of the citizen.

5. Government investment in public corporations: To render essential services create more employment opportunities among others, are sure of the reasons why government invest.

    Factors that determine investment
   1.    The amount of income earned.
   2.    Savings
   3.    Profit
   4.    The amount paid as tax
   5.    The rate of interest
   6.    Expectation
   7.    Business atmosphere
   8.    Political factor

    CONSUMPTION
   Consumption is the sum of current expenditure on goods and services by individuals, firms and government. It is also mean part of income not saved or invested. The level of consumption of an individual depends largely on his level of current income.

    Factors that determine the level of consumption
   1.    The level of income
   2.    Savings
   3.    Expectation of price changes
   4.    The rate of taxes paid
   5.    The influence of other households
   6.    Assets owned
   7.    The rate of interest received
   8.    Business profit

    EVALUATION
   1.    Give five factors that determines the level of consumptions.
   2.    What is Investments?

    
    The Relationship Between Income, Consumption, Savings And Investment
   Income, consumption and savings are related. The amount of income earned (household) determines to a large extent the level of consumption of an individual as well as the amount which can be saved. This is represented by the formula. Y = C+S, where Y = Income, C = Consumption expenditure and S = Savings

    Also, income, consumption and investment are related. The amount of income earned (business sector) determines to a large extent the level of spending on the running overhead cost (consumption) as well as the amount spent on further investment. This is represented by the formula: Y = C + I , where Y = Income , C = Consumption expenditure , I = Investment Expenditures

    In forming an equation with household income and the business sector’s income, we have:
   C + S = C + I
   S = I
   Consumption influences the level of national income. If people consume more, it encourages further production. Economy is at equilibrium when aggregate saving equals aggregate investment and full employment is achieved at this level. We save in order to accumulate capital for investment and for many other personal reasons. There will be no investment without saving. Investment, in turn, creates employment and income for people. Without income, we shall have nothing to save and nothing to spend on consumption of goods and services.

    EVALUATION
   

   1. How is the national income of a country determined?
6. Explain two ways by which members of household dispose their income

    READING ASSIGNMENT
   

   1. Amplified and simplified Economics for SSS by Femi Alonge Chapter 31 page 413 – 425
   2. Fundamentals of Economics for the SSS by R.A.I Anyanwuocha Chapter 32 page 254 – 258
   3. Mathematical Approach to Economics for sss by Kunle A. Nosiru page 177-182

    GENERAL REVISION QUESTIONS
   

   1. Give five reasons why Government participates in business enterprises.
   2. Define ageing population.
   3. Explain the sources of finance available to a public limited liability business.
   4. Explain any three weapons that can be used by a trade union during trade dispute.
   5. What is occupational mobility?

    WEEKEND ASSIGNMENT
   

7. The part of income that is not spent is known as ____ (a) multiplier (b) saving

       (c) expenditure (d) depreciation

   1. All these factors tend to reduce the amount of funds in the circular flow of income except………………. (a) savings (b) grants (c) imports (d) taxes
   2. The real capital investment of a country is a reflection of it’s…………… (a) total debts

      (b) total goods (c) total income (d) total reserve

   3. An expenditure on physical assets which are not for immediate consumption is known as…………… (a) a consumption (b) an investment (c) a liability (d) a saving
   4. ………………is the major determinant in the concepts of saving, investment and consumption. (a) cost of living (b) multiplier (c) standard of living (d) income.

    THEORY
   

8. Identify and explain briefly the two major factors affecting the circular flow of income.
9. Simply explain the concept of income in relation to saving, investment and consumption.

    EQUATION AND CALCULATION OF INCOME DETERMINATION
   CONTENTS
   

10. Y = C + I + a + (x – m)
11. Calculation of APS
12. Calculation of APC
13. Calculation of MPS
14. Calculation of MPC

     NATIONAL INCOME AND ITS CALCULATION
    In calculating the National Income for an open economy where import and export are involved (International Trade). A function such as:
    Y = c + 1 + a + (x-m) could be used in arriving at the aggregate income in this function.
    Y = The value of national income
    C = Aggregate Investment expenditure (consumption)
    I = Private Investment expenditure
    X = Export expenditure
    M = Import expenditure
    Xn = Net exports (Xn >0)

     Example 1
    Below is information concerning the gross national product for a country in 1994 (in billions of naira) by sectors that buy the GNP.
            Heading                Amount
    Personal Consumption expenditures            637.3
    Gross Private domestic investment            452.2
    Government purchase of goods and services        105.3
    Exports of goods and services             1001.
    Imports                        50.3

• What method of national income is used for the above table?
• Calculate the national income of the solution.

   Solution
  

1. The method used is the expenditure method.
2. Since we are concerned with the expenditure method we have.

   GNP = C + I + G + (x – m)
   Substituting GNP = N637. 3 + N453.2 + N105.3 + (N100.1 – N50.3) = N1,245.66

    Example II
   The national income equation of a hypothetical country is expressed as:
   Y = C + I + G
   Where:
   C = a + by
   N100m + ³/_4Y
   I = N20m
   G = N40m
   Where C, I and G are consumption, investment and government expenditure respectively. Calculate the equilibrium level of national income.
   Solution:
   Y = C + I + G
   Y = a + by + I + G
   Substituting into the equation above
   Y = N100m + ³/_4Y + N40m
   Collecting like terms
   (Y – ³/_4Y) = 100 + 20m + N40
   Factorise the RHS
   Y(1 – ¾)
   Y ( ¼ ) = N160m
   Divide both sides by ¼
   Y / ¼ 160
   ¼ = ¼
   Y = 160 x ⁴/₁ = N640m

    PROPENSITIES TO CONSUME
   1. Average propensity to consume (APC)
   This is the ratio of consumption to income. Also, it is the fraction of the national income
   consumed. That is,
       APC = Total National Consumption = C
           Total National Income         Y
   Algebraically
   APC = 1 (as c = y)
   C = Y X APC
   APC >1 as C >Y
   Y = ^C/_APC
   All things being equal, the average propensity to consume falls between zero and unitary.

    Example 1
   Calculate the average propensity to consume. If the national income is N20m and the total National Consumption is N15m
   Solution
   APC = ^C/_Y
   Substituting into the formula above
   APC = N15M
       N20m = 0.75

    Example II
   If the national income is N150m and the average propensity to consume is 0.2. Calculate the total national consumptions.

    Solution:
   Applying
   C = Y x APC
   = N150m x 0.2
   = N30m

    EVALUATION
   A.    Find the national income when the total consumption is N600m and the average propensity to consume is 0.4.
   B.    Calculate the average propensity to consume if the national income is N40m and the total National Consumption is N30m.

    2. Marginal Propensity To Consume (MPC)
   Marginal Propensity to Consume (MPC). This can be defined as the ration of the change in consumption to the change in income that necessitated it. That is,

    MPC = Change in Consumption     = ∆C
       Change in income          ∆Y
   OR

    MPC = ∆C (Infinitesimal Change) – A very Small Change
       ∆Y
   O < MPC < 1
   MPC falls between Zero and one
   Algebraically
   ∆C = MPC x ∆Y and
   ∆Y = ∆C
       MPC

    Example 1
   If total national income increases from N1,500m to N1,800m and the total national consumption increases from N500m to N650m. What is the MPC.
   Solution:
   MPC = ∆C
        ∆Y
   Substituting
   MPC = (650 – 500)m
        1,800 – 1,500
   MPC = N150m = 0.5
        N300

    Example 2
   Given that the total national income increases from N750m to N1000m and the MPC is 0.7, find the change in consumption.
   Solution.
   ∆C = MPC x ∆Y
   ∆Y = N1000m – N750m
        = N250m
   Substituting
   ∆C = 0.7 x N250m
   = N175m
   Example 3
   Determine the change in the total income if the change in the total national consumption is N300m and the MPC is 0.4.
   Solution
   Applying
   ∆Y = ∆C = N300m = N750m
           MPC     0.4

    EVALUATION
   A.    If total national income increases from N2,500m to N2.800m and the total national consumption increases from N700 to N950m. What is the mpc.
   B.    Determine the change in the total national income if the change in the total nation consumption is N600m and the mpc is 0.8

    PROPENSITIES TO SAVE
   1. Average Propensity To Save (APS)
   This is defined as the ratio of savings to income. That is, the ratio of income saved (nationally) to the national income. It is denoted thus:
       AP = Total National Savings = S
           Total National Income     Y
       O < APS < 1 (provided O < S < Y)
       APS = 1(as S = Y)
       APS = O (as S = O) Zero savings

   Algebraically
   S = APS x Y and
   Y = S
   APS
   Example 1
   If total national savings is N50m and the total national income is N500m, then the APS will be thus:
   Solution:
   Applying
   APS = S
       Y
   Substituting
   APS = N50
       N500
   APS = 0.1
   Example 2
   Calculate the total national income if the total national savings is 250m and the APS is 0.2.

    Solution:
   Applying
   Y = S
   APS
   Substituting
   APS = N250
        0.2
   APS = N1,250m

    2. Marginal Propensity To Save (MPS)
   This is defined as the ratio of the change is savings to the change in income that necessitated it. It is denoted thus:
   MPS = Change in Savings ∆S
        Change in income ∆Y

    OR
   MPS = ∆S (infinitesimal change) – A very small change 0 < MPS < 1
   MPS falls between zero and one
   Algebraically,
   ∆S = MPC x ∆Y and ∆S
   ∆Y MPS
   Note: MPS + MPC = 1
       MPS = 1 – MPC

    Example 1
   What is the MPS if the total national income increase from N375 to 450m and the total national savings increases from N85m to N100m
   MPS = ∆S
   ∆Y

    Substituting
   MPS = (100 – 85)
        450 – 375
   MPS = N15m = 0.2
        N75m

    Example II
   If the change in the total national income is N300 and the mps is 0.6, what will be the total national savings.
   Solution:
   ∆S = MPS x ∆Y
   = 3000 x 0.6 = N180m

    Example III
   Given the change in the total national savings is N120mand the MPS is 0.3 calculate the total national income.
   Solution
   Applying
   ∆Y = ∆S
        MPS
   = N120m = N400m
        0.2
   Example IV
   Find the mps when the mpc is 0.6
   Solution
   mpc + mps = 1
   therefore mps = mpc – 1

• mps = 0.6 – 1
• mps = -0.4

  mps = 0.4

   READING ASSIGNMENT
  Amplified and Simplified Economics for SSS by Femi Alonge , Chapter 31 page 413 – 425
  Fundamentals of Economics for the SSS by R.A.I Anyanwuocha Chapter 32 page 254 – 258
  Mathematical Approach to Economics for sss by Kunle A. Nosiru page 177-182

   WEEKEND ASSIGNMENT
  1.    The disposable income of Ade increases by #10 million and her marginal propensity to consume also goes up to #0.6 , how much of the additional will she save? (a) #40,000 ( b) #400,000 ( c) #600,000 (d) #4,000,000
  2.        Given the investment and consumption function of a two sector economy as
  C = 25 + 0.30 y and I = 10 million . What is the equilibrium level of income?
  (a) #50m (b) #500m ( c) #5000m ( d) #5.500m (e ) #5.550m
  3.    If the national income is N150m and the average propensity to consume is 0.2 calculate the total national consumption. (a) N30m (b) N40m (c) 15m (d) 10m
  4.    Calculate the average propensity to consume if the national income is N20m and the total national consumption is N15m. (a) 0.25 (b) 0.17 (c) 0.75 (d) 0.1
  5.    Determine the change in the total national income if the change in the total national consumption is N300m and the MPC is 0.4 (a) N750m (b) N400m (c) N500 (d) N400m

   THEORY
  1.    Explain the term propensity to consume and its effects on the economy
  2.    State the two attributes of propensity to save.