58 The Basics of financial economeTrics
So, in this instance we have k = 2. The multiple linear regression to be
estimated is
y = b 0 + b 1 x 1 + b 2 x 2 + e
where y = the monthly return of an index
x 1 = the monthly change in the Treasury yield
x 2 = the monthly return on the S&P 500
In a simple linear regression involving only x 2 and y, the estimated
regression coefficient b 2 would be the beta of the asset. In the multiple linear
regression model above, b 2 is the asset beta taking into account changes in
the Treasury yield.
The regression results including the diagnostic statistics are shown in
Table 3.4. Looking first at the independent variable x 1 , we reach the same
conclusion as to its significance for all three assets as in the univariate
TAbLE 3.4 Estimation of Regression Parameters for Empirical Duration—Multiple
Linear Regression
Electric
Utility Sector
Commercial
Bank Sector
Lehman U.S. Aggregate
Bond Index
Intercept
b 0 0.3937 0.2199 0.5029
t-statistic 1.1365 0.5835 21.3885
p-value 0.2574 0.5604 0.0000
Change in the Treasury Yield
b 1 –4.3780 –1.9096 –4.0885
t-statistic –3.4143 –1.3686 –46.9711
p-value 0.0008 0.1730 0.0000
Return on the S&P 500
b 2 0.2664 1.0620 0.0304
t-statistic 3.4020 12.4631 5.7252
p-value 0.0008 0.0000 0.0000
Goodness-of-Fit
R 2 0.1260 0.4871 0.9312
F-value 12.0430 79.3060 1130.5000
p-value 0.00001 0.00000 0.00000