Granger causality
Contents
Granger causality¶
General idea:
The cause contains information about the futute of the effect which is not in any other variable (including the past of the effect)
the cause happens before to the effect
the cause has unique information about the future of the effect
where
no information is lost by excluding
Note:
It is possible that both
Theory vs. practice¶
in theory,
contains the infinite past of all variables in the universein practive
includes only a few variables, often only and , and only a few lags
Testing for (pairwise conditional) Granger non-causality¶
if
interpretation: given the information in the past of
and , the past of doesn’t help forecast
intuition for the test: we are asking whether the variance of the forecast errors is significanty smaller when lags of
are included in the predictive regression for .
Granger causality as transfer of information¶
latent variables (more general than future values of observed variables)
how informative (more general than informative/uninformative)
frequency-domain formulation (informative frequencies)