The absolute deterministic version of purchasing power parity (PPP), in which nominal exchange rates move precisely to offset changes in aggregate price levels between national economies, is not generally supported by empirical evidence. Testing PPP with standard regression models permits some...

In situations where a sequence of forecasts is observed, a common strategy is to examine “rationality” conditional on a given loss function. We examine this from a different perspective— supposing that we have a family of loss functions indexed by unknown shape parameters, then given the...