U OF K MBA PROGRAM
Macro‐Economic Investment Theories Eljaili
2006
[email protected]
1‐ Concept of Investment: Investment is the flow of spending that adds to the physical stock of capital. In include spending by both private & public sector on new capital goods that adds to the society’s stock of capital.
2‐ Types of Investments: Classification of investment: 1. Gross Investment: refers to the total spending of supply on new a capital goods. 2. Replacement investment: refers to the spending on a capital goods that were depreciate/ wear out. 3. Net Investment: Gross – Replacement Investments. Another classification of investment: 1. Private investment: Spending on capital goods by private sector. 2. Public Investment: flow of spending on capital goods by government or public sector. Aggregate Investment =private + Public Investment.
Third classification of investment: 1. Business fixed investment: refers to business spending on meeting equipments & structure such as factories. 2. Residential Investment: consisting largely of investment on housing. 3. Inventories Investment: consisting of additional to stock of inventories includes raw materials, goods in process of production, and completed goods held by the firm anticipation of product sale.
3‐ Determinants of Investment: Investment is central topic in macro‐economic for two reasons: 1. Fluctuation investment account for much of the movement of GDP in business cycle. Investment is the most technical (cyclical) ran able of the aggregate demand components. 2. Investment spending determines the rate at which the economy adds to its stock of physical capital and thus helps determine the economy long‐run growth and productivity performance.
4‐ The theory of investment: a. Classical approach: Classical economists viewed the rate of invest as the main determinant of investment. Because interest rate is the cost of capital, which means when a firm plan to invest or to undertake new investment then it need to borrow or take loan to finance this investment. How ever, before that feasibility study must be undertaken on which the expected yield of investment will be compared with the cost of capital. Calculating the expected yields from a new investment is not easy because yields are spread over number of years in the future. One way of comparing the expected yield of an investment to its initial cost is to calculate yields on investment. Investment Decision: Investment decision depends on the result of comparing present value of future yields to initial cost of certain project. If the present value of expected yield exceeds initial cost, investment is profitable and its possible to be undertaken otherwise it is unprofitable and it is unwisely to be undertaken future running costs. The net return from investment can be calculated as: NR = ∑(Rt+i – Ct+i) / (1+r)i : from i=0 to n.(Ot ≤NR). b. Neo‐Classical approach: According to the neo‐classical theory of investment behavior, a profit maximizing firm will employ units of capital until the point is reached at which the expected rate of return on capital called the value of the marginal product of capital, is exactly equal to the user (rental) cost of capital. In other words given the user costs of capital a perfectly competition firm determines its desired capital stock to rent or own by equating the expected rate of return on capital ( the value of the marginal product of capital) to the user rental cost of capital. The desired capital stock is the stock of capital a firm would like to have in the long‐ run. The value of the marginal product of capital is the increase in total revenue attributable to the addition of one more unit of capital. The value of the marginal product is determine by multiplying the marginal product of capital which is the increase in output resulting from using one more unit of capital by the price of final product. Value of marginal product= MP X P.
c. Keynesian approach: ‐ Marginal Efficiency of capital (MEC) or internal rate of return: The marginal efficiency of capital MEC approach to investment is essentially formalization by Keynes in his general theory of employment, money and interest rate for the approach taken by classical economists before him. In simple terms it involve calculating whether its profitable for affirm to make a certain investment but this require some means of comparing cost of the investment with its prospective benefit (in form of profits) in the future. Or compare initial cost outlay of a particular investment with its future net return.
Ot ≤ ∑ (Rt+i – Ct‐i )/ (1+r)n , for i=0 to n
Where r will be marginal efficiency of capitals which can be defined as an interest rate if it were used to discount the net return on an investment would make that investment neither profitable nor unprofitable and investment will be profitable if MEC ≥ r. The MEC approach involves using the technique of discounting to compare the initial cost outlay of a particular investment Ot, with the present value of net return. If scheme produce an income of $2000 per year for five years, and the initial cost of that project is $45000, then MEC for this scheme is calculated in the following way: Ot = ∑ (Rt+i – Ct+i) / (1+m)n , for i=0 to n 45000= 2000/(1+m) m = 28.5 (by using table) Profitable if r < MEC m > r then the project can be undertaken. m < r then the project unprofitable.
‐ Marginal Efficiency of Investment (MEI): One attempt to get from the MEC to the theory of investment is the marginal efficiency of investment (MEI) analysis. This involves making the speed of adjustment from the existing level of the capital stock to some new level as determined by the (MEC), dependent on the behavior of the firm which produce capital goods. The idea is that firm undertaking investment project (purchases capital goods) would prefer to undertake them immediately, but if there is a high demand for capital goods producers of capital goods may experience capacity constrains which preset prevent them from supplying all the orders at once, so that they raise prices. Similarly, when the demand for capital goods is low, producer might lower their prices. These alterations in capital goods prices mean changes in the outlay cost of the investment projects to capital goods producers. Such that firms have to recalculate the yield on their investment project by setting: O’t = ∑ (Rt+i – Ct+i) / (1+m’)n , for i=0 to n (Where O’t is the new outlay cost and m’ is the new marginal efficiency of capital). Repeating this exercise for all different levels of demand for capital goods (and for prices associated with them) and then aggregating in the usual way across firm produce a revised (MEC) schedule incorporating the variations in capital goods prices. This new schedule is called the marginal efficiency of investment (MEI) schedule and is steeper than the MEC schedule. Shown from the figure when interest rate is high (low) investment demand is higher (lower) than on the MEC because capital goods prices are lower (higher).
M
MEI
Higher investment
Lower investment
MEC
Value of the investment
‐ Different between MEC & MEI: i. While the MEC shown relationship between the rate of investment and the desired stock of capital, MEI shows the relationship between the rate of investment and the actual rate of investment per year (MEC shows relationship between rate of investment and capital stock while MEI shows relationship between rate of investment & actual investment). ii. Thus MEC is concerned with a flow. There will be important differences between the capital stock people desire and the capital investment that takes place. This is because there is physical constraining upon the construction of capital goods. ‐ The accelerator principles: The accelerator model asserts that investment spending is proportion to the changes in output and is not effected by the cost of capital. The basic idea of accelerator principle that firms install new capital when they need to produce more, therefore, firms would invest if output was expected to change, but they would not otherwise undertake new investment. The simplest view of the accelerator start from the assumption a fixed rate relating output to the amount of capital normally require to produce it, that is fixed capital output ratio.
K*t = α Yt
It assumes that firms always adjust their capital to their output so that the capital stock of the previous period must be in the ratio to the output of the previous period:
Kt‐1 = α Yt‐1
Net investment is the growth in capital stock between periods:
It = K*t – Kt‐1 = α Yt – α Yt‐1 = α (Yt – Yt‐1)
It = α ΔY
Thus net investment is proportional to the growth of output, rather than its level. Rising output brings about positive net investment and constant output brings about zero net investment and falling output brings about negative net investment.