In this paper, we propose Phillips-Perron type, semiparametric testing procedures to distinguish a unit root process from a mean-reverting exponential smooth transition autoregressive one. The limiting nonstandard distributions are derived under very general conditions and simulation evidence...

The concept of nonparametric smoothing is a central idea in statistics that aims to simultaneously estimate and modes the underlyingstructure. The book considers high dimensional objects, as density functions and regression. The semiparametric modeling technique compromises the two aims,...