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INTERDISCIPLINARY JOURNAL OF CONTEMPORARY RESEARCH IN BUSINESS<br />

JANURAY 2011<br />

VOL 2, NO 9<br />

Two steps are <strong>in</strong>volved to implement<strong>in</strong>g this procedure. In the first step optimum lag<br />

length (k) <strong>of</strong> VAR and the maximum order <strong>of</strong> <strong>in</strong>tegration (dmax) <strong>of</strong> the variables <strong>in</strong> the system<br />

is determ<strong>in</strong>ed. Then a level VAR is estimated with a total <strong>of</strong> k+dmax lags. In the second step a<br />

standard Wald tests is applied to the first k VAR coefficient matrix to make Granger causal<br />

<strong>in</strong>ference. In order to test for Toda and Yamamoto (1995) based Granger causality between<br />

core variables (LnNYt, LnHt, LnMXt, LnSMXt and LnPXt) we estimate the follow<strong>in</strong>g<br />

VAR(k+dmax) model:<br />

� LnNYt<br />

� �C1<br />

�<br />

� � � �<br />

�<br />

LnHt<br />

� �<br />

C2�<br />

� LnMX t � � �C3<br />

� �<br />

� � � �<br />

�LnSMX<br />

t � �C4<br />

�<br />

�<br />

� LnPX �<br />

�<br />

�<br />

�<br />

�<br />

t C5<br />

�<br />

k �d<br />

max<br />

�<br />

i�1<br />

��1i<br />

�<br />

�<br />

�2i<br />

��3i<br />

�<br />

��<br />

4i<br />

�<br />

��5i<br />

�<br />

�<br />

�<br />

�<br />

�<br />

1i<br />

2i<br />

3i<br />

4i<br />

5i<br />

�<br />

�<br />

�<br />

�<br />

�<br />

1i<br />

2i<br />

3i<br />

4i<br />

5i<br />

�<br />

�<br />

�<br />

�<br />

�<br />

1i<br />

2i<br />

3i<br />

4i<br />

5i<br />

�1i<br />

� � LnNYt<br />

�i<br />

� ��<br />

8t<br />

�<br />

�<br />

� � � � �<br />

2i<br />

� �<br />

LnHt<br />

�i<br />

� �<br />

�9t<br />

� …… (12)<br />

�3i<br />

� � LnMX t �i<br />

� � ��10t<br />

�<br />

� � � � �<br />

�4i<br />

� �LnSMX<br />

t �i<br />

� ��11t<br />

�<br />

� �<br />

�<br />

�<br />

�<br />

�<br />

�<br />

�<br />

�<br />

�<br />

5i<br />

LnPX t �i<br />

�12t<br />

�<br />

where C‘s are the <strong>in</strong>tercepts. θ‘s, β‘s, η‘s, ρ‘s and λ‘s are the coefficients <strong>of</strong> LnNYt,<br />

LnHt, LnMXt, LnSMXt and LnPXt respectively. �‟s are error terms that are assumed to be<br />

white noise. Hav<strong>in</strong>g estimated above system <strong>of</strong> equations, usual Wald tests are then applied to<br />

the first k coefficient matrices us<strong>in</strong>g the standard χ 2 -statistics. The hypothesis can be drawn as<br />

LnNYt ―Granger-causes‖ LnHt if β1i ≠ 0, LnMXt if η1i ≠ 0, LnSMXt if ρ1i ≠ 0 and LnPXt if λ1i ≠<br />

0. Similarly, other hypothesis can be drawn for unidirectional and bidirectional causality<br />

among rest <strong>of</strong> the under <strong>in</strong>vestigat<strong>in</strong>g variables.<br />

5. Empirical Results<br />

Before test<strong>in</strong>g for co<strong>in</strong>tegration for the analysis <strong>of</strong> short and long run dynamics, the<br />

unit root test is used <strong>in</strong> order to <strong>in</strong>vestigate the stationarity properties <strong>of</strong> data and all variables<br />

are found stationary at first difference. After <strong>in</strong>vestigat<strong>in</strong>g the order <strong>of</strong> <strong>in</strong>tegration, the study<br />

proceeds for co<strong>in</strong>tegration, parsimonious ECM Model and Granger causality test. For the<br />

<strong>in</strong>vestigation <strong>of</strong> dynamic behavior <strong>of</strong> all variables, impulse response function and variance<br />

decomposition is also carried out.<br />

5.1 Order <strong>of</strong> Integration<br />

ADF unit root test is employed to test for the stationarity <strong>in</strong> logarithmic form <strong>of</strong> NYt, Kt, Lt, Ht,<br />

Xt, MXt, SMXt, PXt and CMt at level and then first difference <strong>of</strong> each series. The results <strong>of</strong> the<br />

ADF test at level and first difference are reported <strong>in</strong> Table 1, by tak<strong>in</strong>g <strong>in</strong>to consideration<br />

trend variable and without trend variable <strong>in</strong> the regression. Based on Table 1 at level, the tstatistics<br />

for all series from ADF test are statistically <strong>in</strong>significant to reject the null hypothesis<br />

<strong>of</strong> non-stationary at 5% significance level. This <strong>in</strong>dicates that these series are non-stationary at<br />

their level form. Therefore, these variables have a unit root problem or they share common<br />

stochastic movements.<br />

COPY RIGHT © 2011 Institute <strong>of</strong> <strong>Interdiscipl<strong>in</strong>ary</strong> Bus<strong>in</strong>ess <strong>Research</strong> 452

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