This paper uses spectral analysis to provide evidence that cycles have characterized the following time series: all ter rorist events, skyjackings, kidnappings, barricade and hostage taking and all events not involving hostages. The series for all events ha d a periodicity of 28 months, while...

A general theory of interpersonal exchange is developed from a public goods, public choice point of view and within an analytical context that assesses both the benefits and the costs of social interaction. Social transaction benefits and costs are specified as a composite function of...