Promotions are at the same time beloved and feared by both food retailers and branded goods manufacturers in today’s retail environment. Beloved because they attract smart customers and generate an immediate effect on a brand’s sale. Feared because there is uncertainty about the...

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...