Test for presence of identifiable seasonality

This test combines the values of the $F$-statistic of the parametric test for stable seasonality and the values of the moving seasonality test, which was described above.

The test statistic is:

$T = \left( \frac{\frac{7}{F_{S}} + \frac{3F_{M}}{F_{S}}}{2} \right)^{\frac{1}{2}}$, [1]

where $F_{S}$ is a stable seasonality test statistic and $F_{M}$ is moving seasonality test statistic. The test checks if the stable seasonality is not dominated by moving seasonality. In such a case the seasonality is regarded as identifiable. This test statistic is used in the combined seasonality tests (see section Combined seasonality test. The detailed description of the test is available in LOTHIAN, J., and MORRY, M. (1978).