This paper proposes a new test based on a Fourier series expansion to approximate the unknown functional form of a nonlinear time-series model. The test specifically allows for structural breaks, seasonal parameters and time-varying parameters. The test is shown to have evry good size and power...

Transnational terrorism data are difficult to forecast because they contain an unknown number of structural breaks of unknown functional form. The rise of religious fundamentalism, the demise of the Soviet Union, and the rise of al Qaeda have changed the nature of transnational terrorism. 'Old...

We investigate the possibility that the Taylor rule should be formulated as a threshold process such that the Federal Reserve acts more aggressively in some circumstances than in others. It seems reasonable that the Federal Reserve would act more aggressively when inflation is high than when it...

Supplement 7. Abstract Currently Unavailable.