This paper develops univariate seasonal unit root tests based on spectral regression estimators. An advantage of the frequency domain approach is that it enables serial correlation to be treated non-parametrically. We demonstrate that our proposed statistics have pivotal limiting distributions...

type="main" <p>This paper uses a macroeconomic model of investment behaviour to identify cyclical activity in UK investment. Various cycles are detected and their lengths are estimated. As a new contribution to the business cycle literature, we estimate the gestation lags inherent in investment...</p>