<p> Interest Rates: Calculating the Yield of an Asset </p><p>- Source: Mishkin and Serletis, Ch. 4</p><p>- Interest rate: - a summary measure of the return on a financial asset, </p><p>- importance: a measure of the benefit to the lender and a measure of the cost to the borrower.</p><p>- We need a measure of this ‘Interest Rate’:</p><p>- economists use a measure of the ‘internal rate of return’ on an investment. </p><p>- this is also called the ‘Yield-to-Maturity’ (referred to as ‘Yield’ below).</p><p>Yield (Internal Rate of Return):</p><p>- Technically: the interest rate that equates the present value of cash flow from an asset with its cost. </p><p> cost? could be the price of the asset; could be the present value of payments made to purchase the asset. </p><p>- It measures the average annual return on the amount invested that gives a payment stream of the same value as the asset actually pays.</p><p>- Yield is what economists mean by an “interest rate”.</p><p>- Why is a measure of yield needed?</p><p>- allows comparison of the generosity of very different payment streams. </p><p> e.g. see text examples of the simple loan, discount bond, coupon bond.</p><p>1 Calculating the Yield using Present Values: </p><p>- Say an asset provides a stream of payments:</p><p>A1 , A2 , A3 ,.... AN-1 , AN </p><p> where Aj is the payment received in period j (think of a period as a year)</p><p>- Dollars received in different years are not of equivalent value.</p><p>$1 in the future is worth less than $1 now.</p><p>Why? $1 received now could be invested at a rate of return "i", giving the person: </p><p>$1 x (1+i) > $1 in one year</p><p> e.g. i=.05 (5%) gives $1.05 in 1 year.</p><p>How much is $1 in one-year worth now? i.e. what is its present value</p><p>Answer: </p><p> why? investing this amount at a return i now would give $1 in one year</p><p>(1+i) x = 1</p><p>Similarly, the values now (present values) of $1 received in:</p><p> two years: (investing this for 2 years at i gives $1 in 2 years) three years: N years: - So the value in present dollars of the stream of payments: </p><p>A1 , A2 , A3 ,.... AN-1 , AN </p><p> i.e., its Present value is:</p><p>2 - Another interpretation of the last expression? </p><p>- Each term shows how much has to be invested now at a rate of return "i" to receive the payment Ak in 'k' years. </p><p>- sum of the terms: total investment now that would give this stream of returns if the return (yield) was "i" in every period.</p><p>- so "i" is the ‘average annual yield’ (average: since it is the same over the period 1 to N).</p><p>- Define “D” as the cost of (or the amount deposited in) the asset.</p><p>- Then if we know D and A1 , A2 , A3 .... AN you can calculate the yield from:</p><p>(1)</p><p> i.e.. solve this for "i" (as before Aj is the payment from the asset in year j).</p><p>‘i’ is the ‘internal rate of return’ or ‘average annual yield’ on the asset.</p><p>3 Examples: </p><p>Treasury Bill or Commerical Paper: </p><p>- Text discussion: this is an example of a “discount bond”.</p><p>- 1 year to maturity:</p><p>- One payment of A is made at maturity (one year in the future).</p><p>- D is the price of the Treasury bill (amount invested), </p><p>- Of course: D<A</p><p>- The yield is obtained by solving the following for i:</p><p>D = </p><p> e.g.,T-Bill auction December 18, 2012:</p><p>A=100 (practice is to quote payment as 100)</p><p>D = 98.899 (price paid -- stated as a discount on A)</p><p>98.899 = so: i = .0111 ( i.e. 1.11%)</p><p>4 A Fixed Payment for N periods </p><p>- Text: Fixed-Payment Loan.</p><p>- Assets with this kind of payment stream: annuity, amortized loan (repay the loan in equal installments), preferred share.</p><p>- Involves a fixed payment in each time period (year) for some specified length of time (N years). Fixed: so A same across time</p><p>- Then:</p><p> or:</p><p>-The terms in the brackets [.] are a geometric series of the form:</p><p> i 2 3 N ia = a + a + a + ... + a </p><p> i means this is a sum of terms from i=1 to N)</p><p> i 2 3 N i a = a + a + a + ... + a (series) i 2 3 N+1 a i a = a + a + ... + a (series times 'a') ______i N+1 (1-a) i a = a - a (difference: between series and series times 'a' )</p><p>So: i N+1 i a = (a - a ) / (1-a)</p><p>Use this last expression to replace [.] in the annuity where a = , this gives:</p><p>5 or after multiplying the top and bottom of [.] by (1+i):</p><p>D</p><p> i.e., a much simpler expression.</p><p>- If N is infinity (payments forever) this is a perpetuity or consol and the expression is very simple:</p><p>D = (why? if N→∞ and i>0)</p><p>- The expression for a perpetuity can also give a reasonable approximation for other long-lived assets.</p><p> e.g., a house that will last 100 years (N large) it provides a return of A=$1000x12 per year (saved rent), and its price is D=$200,000</p><p>200,000 = 12000/i </p><p> i = .06 (6%)</p><p>6 Bond (text: “coupon bond”)</p><p>- N years to maturity</p><p>- Annual coupon payments of A dollars (see below for non-annual)</p><p>- M: payment received when it matures or is sold (face value or resale price if sold before maturity)</p><p>D = A + A + A +....+ A + M (1+i) (1+i)2 (1+i)3 (1+i)N (1+i)N</p><p>Like an annuity, except for the last term.</p><p>- the average annual yield can then be obtained by solving for i.</p><p>- No simple solution for i: solve numerically (financial calculator will do this, Solver in Excel)</p><p> e.g. say the face value is $1000 (=M is held until maturity); say the coupon rate is 10% (so the coupon payments A=.1x$1000=$100) and N=8 (eight years to maturity) and the price is $889.20</p><p>$889.20</p><p>Solving for i gives: i=.1225 (12.25%)</p><p>- Loans requiring a fixed payment per period and a final payment of different size (e.g.,mortgages) have the same type of payment stream as the bond.</p><p>- yield can be calculated in the same way as the bond</p><p>7 Asset Price and Yield:</p><p>- Take the general expression:</p><p>D = A1 + A2 + A3 +....+ AN (1+i) (1+i)2 (1+i)3 (1+i)N </p><p>D = the amount invested, the cost or price of the asset,</p><p>Aj= payment from the asset in period j.</p><p>- Given the payment stream (Aj), i and D are inversely related:</p><p>- higher D means lower i.</p><p> i.e. the more you pay for a given stream of payments the lower your yield.</p><p> e.g., 1-year Treasury bill (worth 100 at maturity) Price 98.899 Yield .0111 (see above) Price 95.0 Yield .0526</p><p>- This works both ways.</p><p>- if yields on other assets are rising </p><p>- price on this asset must fall if it is to pay a competitive return.</p><p>- this gives rise to “interest rate risk”: resale price of an asset will change with changes in interest rates. </p><p>- An important point: given a value of ‘i’ and a payment stream (Aj) the equation tells us what the competitive price of the asset would be (D). </p><p>- asset price is higher the higher are the Aj;</p><p>- asset price is lower the higher is the yield on alternative assets.</p><p>8 Interest Rates and Yields:</p><p>- In economics the terms are used interchangeably. </p><p>- But an asset sometimes has a stated “interest rate” that differs from its yield. </p><p> e.g. bond paying an x% coupon (the coupon rate is sometimes referred to as the interest rate on the bond)</p><p>- yield will depend both on this coupon rate and the difference between the price of the bond and the size of the final payment (face value). </p><p>Real and Nominal Yields </p><p>- The yield calculations above ignore the effects of inflation on the value of money payments in the future.</p><p>- Inflation involves a transfer of purchasing power from the lender to the borrower</p><p>- Lending and borrowing decisions will likely be made on the basis then of inflation-adjusted yields, i.e., real yields.</p><p>- Future rates of inflation are unknown at the time a financial asset is issued. </p><p>- lenders and borrowers must use an estimate of the expected rate of future inflation.</p><p>- Upon maturity, the actual real yield can be calculated.</p><p>9 Calculating real yields</p><p>- Say that is the expected annual rate of inflation over the relevant time period.</p><p>The stream of future payments:</p><p>A1 , A2 , A3 ,.... AN-1 , AN </p><p> will (in real terms) be worth: </p><p>2 3 N-1 N A1/(1+) , A2 /(1+) , A3 /(1+) ,... AN-1 /(1+) , AN /(1+) </p><p>- where (1+) , (1+)2, (1+)3 discount each payment for inflation. </p><p>- form of the inflation discount factor is just as with present value calculations. </p><p> i.e. a payment of A1/(1+) now will be worth the same as </p><p>A1= (1+) x A1/(1+) in one year. </p><p>The real yield (ir) can be obtained by solving:</p><p>D = A1 + A2 + ... + AN (2) 2 N (1+)(1+ir) {(1+) (1+ir)} {(1+)(1+ir)}</p><p> i.e., just add an additional discount factor to each term to adjust for inflation.</p><p>- Compare this to the yield equation used to calculate the nominal yield (i):</p><p>D = A1 + A2 + A3 +....+ AN (1+i) (1+i)2 (1+i)3 (1+i)N </p><p>10 so, it must be that:</p><p>(1+) (1+ir) = (1+i)</p><p> or (1+ir)= (1+i)/ (1+) </p><p> ir= { (1+i)/ (1+) } –1 (see text footnote 7, p. 83)</p><p>- This can be used to obtain the real yield when information on the nominal yield and rate of inflation is known.</p><p>- A common rule-of-thumb approximation is:</p><p>Real yield = Nominal yield - expected inflation rate</p><p>= i - </p><p>( why? The nominal yield can also be written as:</p><p> i = ir + + ir</p><p> if the last term is small then the approximation will be quite good)</p><p>- Data? See example and Figure 4-1.</p><p>11 - “Real return bonds” or “indexed bonds”: </p><p>- stream of payments is adjusted for inflation so inflation does not change the purchasing power of the payments. </p><p>- Interesting implication of real return bonds?</p><p>- two bonds: identical except one is indexed and the other isn’t.</p><p>- difference in yields reflects expectations of future inflation over the term to maturity of the bonds. </p><p>(ASIDE: Calculations of the real yield above assume inflation rate is constant. </p><p> e.g. 2% (=.02) over the relevant period.</p><p>- if it is expected that the inflation rate could differ over time</p><p> e.g. ,,.. are expected inflation rates.</p><p> then each term (1+)t in equation (2) would need to be replaced with :</p><p>(1+)(1+)(1+)...(1+t)</p><p> then solve for ir )</p><p>12 An Extension: Yields on Assets that Make Multiple Payment per Year</p><p>- What if payments received are are made "m" times per year?</p><p>- A possibility? Use the same idea as above to compute an average yield for a "1/m year" period.</p><p> e.g., m=2 calculate an “average semi-annual yield”. m=4 calculate an “average quarter-annual yield”.</p><p>- This involves taking the equation above, but now the N year asset makes N·m payments:</p><p>D = A1 + A2 + A3 +....+ ANm (3) 2 3 N·m (1+im) (1+im) (1+im) (1+im) </p><p> solving for im gives the average 1/m period yield </p><p>(N·m = is the total number of payments received</p><p> e.g. an asset making semi-annual payments (m=2) over 10 years (N=10) makes 20 payments (10·2).</p><p>13 How to annualize im?</p><p>- We would like to be able to compare im to average annual yields from above.</p><p>- The most common convention is to use iA as the measure of the annual yield where iA is defined:</p><p> iA = m∙ im</p><p> so: </p><p>(1+im) = (1+iA/m)</p><p> substitute this into (3) to get (4).</p><p>For the N-year asset with m annual payments:</p><p>D = A1 + A2 + A3 + . . . + ANm (4) 2 3 Nm (1+ iA/m) (1+ iA/m) (1+ iA/m) (1+ iA/m)</p><p>Examples:</p><p>- Bill or Paper with 3-month term to maturity:</p><p>D = A (1+ iA/m) m=365/(days to maturity)</p><p>Solving for iA:</p><p> iA = m x (100-D)/D</p><p> e.g. December 18, 2012 auction (maturity in 98 days): </p><p>D= 99.738 , m = 365/98 , so iA = .00980 (0.980%)</p><p>14 (Latest results: http://www.bankofcanada.ca/markets/government-securities-auctions/ )</p><p>- Yield on a N -year bond that makes “m” equal payments per year and then its face value (M) at maturity can be calculated as: </p><p>D = A + A + A + . . . + A + M 2 3 Nm Nm (1+ iA/m) (1+ iA/m) (1+ iA/m) (1+iA/m) (1+ iA/m)</p><p> solve this for iA. </p><p>- Common for bonds to make coupon payments every 6 months.</p><p>- Example: 10 year Government of Canada bond issued in 2012, matures June 2022. Coupon: 2.75 (so A=2.75/2 every 6 months), M=100, D=108.9, iA=.01765 (1.765% ).</p><p>15 Appendix: An alternative way to annualize im</p><p>- Could calculate im as above then solve the following for i: </p><p> m (1+im) = (1+i)</p><p> where i is the average annual yield.</p><p> i.e., the first term shows what $1 invested at the rate im for m periods (one year) pays at the end of m periods</p><p>1/m so: (1+im) = (1+i)</p><p> substitute this into (3) to get (5).</p><p>- So the average annual yield when payments are made m times a year could be calculated from:</p><p>D = A1 + A2 + A3 +....+ ANm (5) (1+i)1/m (1+i)2/m (1+i)3/m (1+i)N </p><p>16</p>
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages16 Page
-
File Size-