Trend, Unit Root and Structural Change in Macroeconomic Time Series

The unit root hypothesis has attracted a considerable amount of work in both the economics and statistics literature. Indeed, the view that most economic time series are characterized by a stochastic rather than deterministic nonstationarity has become prevalent. The seminal study of Nelson and Plosser (1982) which found that most macroeconomic variables have a univariate time series structure with a unit root has catalysed a burgeoning research program with both empirical and theoretical dimensions.