Springer Texts in Business and Economics
Using EViews, Qt+i is simply Q(1) and one can set the sample range from 1954-1976
a. The OLS regression over the period 1954-1976 yields RSt = -6.14 + 6.33 Qt+1 - 1.67 Pt
(8.53) (1.44) (1.37)
with R2 = 0.62 and D. W. = 1.07. The t-statistic for у = 0 yields
t = -1.67/1.37 = -1.21 which is insignificant with a p-value of 0.24.
Therefore, the inflation rate is insignificant in explaining real stock returns.
LS // Dependent Variable is RS Sample: 1954 1976 Included observations: 23
Variable |
Coefficient |
Std. Error t-Statistic |
Prob. |
|
C |
-6.137282 |
8.528957 -0.719582 |
0.4801 |
|
Q(1) |
6.329580 |
1.439842 4.396024 |
0.0003 |
|
P |
-1.665309 |
1.370766 -1.214875 |
0.2386 |
|
R-squared |
0.616110 |
Mean dependent var |
8.900000 |
|
Adjusted R-squared |
0.577721 |
S. D. dependent var |
21.37086 |
|
S. E. of regression |
13.88743 |
Akaike info criterion |
5.383075 |
|
Sum squared resid |
3857.212 |
Schwarz criterion |
5.531183 |
|
Log likelihood |
91.54095 |
F-statistic |
16.04912 |
|
Durbin-Watson stat |
1.066618 |
Prob(F-statistic) |
0.000070 |
b. The D. W. = 1.07. for n = 23 and two slope coefficients, the 5% critical
values of the D. W. are dL = 1.17 and dU = 1.54. Since 1.07 < dL, this
indicates the presence of positive serial correlation.
c. The Breusch and Godfrey test for first-order serial correlation runs the regression of OLS residuals et on the regressors in the model and et_i. This yields
et = -4.95 + 1.03 Qt+1 + 0.49 Pt + 0.45 et_
(8.35) (1.44) (1.30) (0.22)
with R2 = 0.171 and n = 23. The LM statistic is nR2 which yields 3.94. This distributed as x1 under the null hypothesis and has a p-value of 0.047. This is significant at the 5% level and indicates the presence of first-order serial correlation.
Breusch-Godfrey Serial Correlation LM Test:
F-statistic 3.922666 Probability 0.062305
Obs* R-squared 3.935900 Probability 0.047266
Test Equation:
LS // Dependent Variable is RESID
Variable |
Coefficient |
Std. Error |
t-Statistic |
Prob. |
C |
-4.953720 |
8.350094 |
-0.593253 |
0.5600 |
Q(1) |
1.030343 |
1.442030 |
0.714509 |
0.4836 |
P |
0.487511 |
1.303845 |
0.373903 |
0.7126 |
RESID (-1) |
0.445119 |
0.224743 |
1.980572 |
0.0623 |
d. The Cochrane-Orcutt yields the following regression RS* = - 14.19 + 7.47 Q* , - 0.92 P*
(9.34) (1.20) + 1 (1.63)
where RS* = RSt — pRSt_1, Qt*+1 = Qt+1 — pQt and Pt* = Pt — pPt_1 with
Pco = 0.387.
e. The AR(1) options on EViews yields the following results:
RSt = —7.32 + 5.91 Qt+1 — 1.25 Pt
(7.92) (1.36) (1.28)
with R2 = 0.68. The estimate of p is p = —0.027 with a standard error of 0.014 and a t-statistic for p = 0 of —1.92. This has a p-value of 0.07. Note that even after correcting for serial correlation, Pt remains insignificant while Qt+1 remains significant. The estimates as well as their standard errors are affected by the correction for serial correlation. Compare with part (a).
PRAIS-WINSTEN PROCEDURE
LS // Dependent Variable is RS Sample: 1954 1976 Included observations:23 Convergence achieved after 4 iterations
Variable |
Coefficient |
Std. Error |
t-Statistic |
Prob. |
C |
-7.315299 |
7.921839 |
-0.923435 |
0.3674 |
Q(1) |
5.905362 |
1.362572 |
4.333981 |
0.0004 |
P |
-1.246799 |
1.277783 |
-0.975752 |
0.3414 |
AR(1) |
-0.027115 |
0.014118 |
-1.920591 |
0.0699 |
R-squared |
0.677654 |
Mean dependent var |
8.900000 |
Adjusted R-squared |
0.626757 |
S. D. dependent var |
21.37086 |
S. E. of regression |
13.05623 |
Akaike info criterion |
5.295301 |
Sum squared resid |
3238.837 |
Schwarz criterion |
5.492779 |
Log likelihood |
-89.53155 |
F-statistic |
13.31429 |
Durbin-Watson stat |
1.609639 |
Prob (F-statistic) |
0.000065 |
Inverted AR Roots |
-.03 |