A punctuated equilibrium model of biological evolution with relative fitness between different species being the fundamental driving force of evolution is introduced. Mutation is modeled as a fitness updating cellular automation process where the change in fitness after mutation follows a...

We examine the volatility dynamics of NYMEX natural gas futures prices via the partially overlapping time‐series model of Smith (2005. Journal of Applied Econometrics, 20, 405–422). We show that volatility exhibits two important features: (1) volatility is greater in the winter than in the...

In this article, we show that vehicle type ownership is spatially dependent at both the regional and household-level even after controlling for income and population density. We discuss reasons for the existence of spatial effects in vehicle ownership, and note potential implications for...

This paper investigates the ability of the Federal Reserve to manipulate the overnight rate without open market operations (which Demiralp and Jorda (2000) term the announcement effect), using high-frequency, open-market-desk data. Using similar data, Hamilton (1997) takes advantage of forecast...