It has long been recognized that aggregating time series introduces correlation between consecutive values of the aggregated observations (see Working (1960)). This paper investigates the effect of aggregation on the relation between variables assuming that the data generating process involves...

Unit root tests for time series with level shifts are considered. The level shift is assumed to occur at a known time point. In contrast to some other proposals the level shift is modeled as part of the intercept term of the stationary component of the data generation process which is separated...