Equation IV explains the dependency of the variance of the error terms on the past error terms and also on the
variances itself. Where ht is the variance of the error term and the variance is dependent on the variance of the
error term at time t-1 and dependent on the past error terms too. w0 is the error term at time t, w1 is the value of
the error term at time t-1 and w2 is the value of the error term at time t-2 . ht-1 is the variance of the error term at
time t-1 and ht-2 is the variance of the error term at time t-2. The heteroskedasticity has been checked by using
Lagrange Multiplier (LM) test. Granger causality test has also been applied to test the causation among the
macroeconomic variables.