A new test is proposed for the null of absence of serial correlation. The test uses a data-driven smoothing parameter. The resulting test statistic has a standard limit distribution under the null. The smoothing parameter is calibrated to achieve rate-optimality against several classes of...

This study measures purchasing power parity (PPP) by means of the dynamic-factor errorcorrection model (DF-ECM) approach. Under this new approach, PPP is embedded in latent disequilibrium factors, which are extracted from a large variable set of bilateral price disparities; the factors are then...