When working with time series data observed at intervals smaller than a year, it is often necessary to test for the presence of seasonal unit roots. One of the most widely used methods for testing seasonal unit roots is that of HEGY, which provides test statistics with non-standard...

Basándose en la literatura existente, en este trabajo se propone una metodología para el estudio gráfico y analítico del componente estacional en una serie temporal. El objetivo del análisis es determinar si el componente estacional responde a un comportamiento determinista o estocástico....

[EN] The relationship between the unemployment and the international immigration is getting interest while the differences between poor and rich countries are stressed. The poor countries offer cheap work force to occupy less qualified jobs in rich countries, with citizen increasingly demanding...

The seasonal stability tests of Canova & Hansen (1995) (CH) provide a method complementary to that of Hylleberg et al. (1990) for testing for seasonal unit roots. But the distribution of the CH tests are unknown in small samples. We present a method to numerically compute critical values and...