Lecture 5 Historical Interest Rate Movements Term Structure Shapes Normal upward sloping Inverted Common Term Structure Shapes Level Humped 12 Interest Rate (%) • • • • 10 8 Upward Sloping 6 Inverted Level 4 Humped 2 0 1 3 5 Years 10 30 How Do Curves Shift? • Litterman and Scheinkmann (1991) investigated the factors that affect yield movements • Over 95% of yield changes are explained by a combination of three different factors – Level – Steepness – Curvature • Rates of maturities shift by approximately the same amount • Also called a parallel shift Yield Level Shifts Maturity • Short rates move more (or less) than longer term interest rates • Changes the slope of the yield curve Yield Steepness Shifts Maturity • Shape of curve is altered • Short and long rates move in one direction, intermediate rates move in the other Yield Curvature Shifts Maturity Characteristics of Historical Interest Rate Movements • Rule out negative interest rates • Higher volatility in short-term rates, lower volatility in long-term rates • Mean reversion (weak) • Correlation between rates closer together is higher than between rates far apart • Volatility of rates is related to level of the rate Summary Statistics for Historical Rates (1953-2001) http://www.federalreserve.gov/releases/H15/data.htm Normal 66.9% Shape Inverted Humped 10.7% 15.3% Yield Statistics 1 yr. 3 yr. 5 yr. Mean 6.04 6.42 6.58 S.D. 2.93 2.82 2.78 Skew ness 1.03 0.90 0.84 Exc. Kurtosis 1.35 0.90 0.67 Percentiles 1 yr. 3 yr. 5 yr. 1% 1.11 1.60 1.95 5% 2.26 2.58 2.75 95% 12.04 12.09 12.40 99% 15.00 14.66 14.56 Corr (1 yr,10 yr) = 0.943 Other 7.1% 10 yr. 6.74 2.75 0.76 0.34 10 yr. 2.38 2.92 12.43 14.28 Run Graph Show of Interest Rates • Go to: http://www.cba.uiuc.edu/~s-darcy/present/casdfa3/intmodels.html • • • • Download Graph Show Click on Historical (4/53-5/99) Click on Start Graph Show You may want to shorten the time interval to speed up the process • Note how interest rates have moved over the last 46 years • Pay attention to the level of interest rates, the shape of the yield curve and the volatility over time Current Interest Rates • Yields • Spot rates • Implied forward rates Yield Curve December 2001 7 6 Interest Rate 5 4 3 2 1 0 0 5 10 15 Years to Maturity 20 25 30 Distortions • U. S. Government stopped issuing 30 year bonds in October, 2001 • Reduced supply of long term bonds has increased their price, and reduced their yields • Effect has distorted the yield curve Conclusion • Interest rates fluctuate • Interest rate models are used to predict future interest rate movements • Historical information useful to determine type of fluctuations that occur – – – – Shapes of term structure Volatility Mean reversion Long run mean levels • Don’t assume best model is the one that fits past movements the best