In this paper the seasonal unit root test of Hylleberg et al. (1990) is generalized to cover a heterogenous panel. The procedure follows the work of Im, Pesaran and Shin (2002). Test statistics are proposed and critical values are obtained by simulations. Moreover, the properties of the tests...

We investigate hysteresis and persistence behaviour in the course of unemployment in EU countries and US states by means of first and second generation panel unit root tests. While the former tests assume independent cross sections, the latter control for dependencies. The first generation tests...