What is the minimum number of time periods required to reliably conduct a Granger causality test? I have a time series with only six data points, and I would like to know if it is possible to conduct Granger causality tests on it.
Specifically, I want to examine cultural values from the World Value Survey, which collects data in "waves" that span five years each. So, the time points are:
Wave 6 (2010-2014)
Wave 5 (2005-2009)
Wave 4 (1999-2004)
Wave 3 (1995-1998)
Wave 2 (1990-1994)
Wave 1 (1981-1984)
Given that there are only five or six data points (there's a gap between Wave 1 and Wave 2), is the Granger causality test at all feasible here?
I know that this is a slightly different question, but if six time periods is too few, are there any appropriate causality tests I could run?