Existing studies generally reject purchasing power parity (PPP) on datasets from countries that have been affected by large real shocks, including Norway. However, we offer strong evidence of PPP between Norway and its trading partners during the post-Bretton Woods period, in which the Norwegian...

This paper constructs tests for the presence of nonlinearity of unknown form in addition to a fractionally integrated, long memory component in a time series process. The tests are based on artificial neural network structures and do not restrict the parametric form of the nonlinearity. The...

This paper investigates GLS detrending procedures for unit root tests against nonlinear stationary alternative hypotheses where deterministic components are assumed present in the series under investigation. It is found that the proposed procedures have considerable power gains in a majority of...

This paper considers estimation and inference in some general non linear time series models which are embedded in a strongly dependent, long memory process. Some new results are provided on the properties of a time domain MLE for these models. The paper also includes a detailed simulation study...

Interest in the interface of nonstationarity and nonlinearity has been increasing in the econometric literature. The motivation for this development maybe be traced to the perceived possibility that processes following nonlinear models maybe mistakenly taken to be unit root or long-memory...

Interest in the interface of nonstationarity and nonlinearity has been increasing in the econometric literature. This paper provides a formal method of testing for nonstationary long memory against the alternative of particular forms of nonlinerarity. The nonlinear models we consider are ESTAR...

Recent advances in testing for the validity of Purchasing Power Parity (PPP) focus on the time series properties of real exchange rates in panel frameworks. One weakness of such tests, however, is that they fail to inform the researcher as to which cross-section units are stationary. As a...

Fund-of-funds (FoF) managers face the task of selecting a (relatively) small number ofhedge funds from a large universe of candidate funds. We analyse whether such a selectioncan be successfully achieved by looking at the track records of the available funds alone,using advanced statistical...

Macroeconomic time series often involve a threshold effect in theirARMA representation, and exhibit long memory features. In this paperwe introduce a new class of threshold ARFIMA models to account forthis. The threshold effect is introduced in the autoregressive and/or thefractional integration...

We test for state-dependent bias in the European Central Bank's inflation projections. We show that the ECB tends to underpredict when the observed inflation rate at the time of forecasting is higher than an estimated threshold of 1.8%. The bias is most pronounced at intermediate forecasting...