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...

No matter how pronounced intraday patterns may appear, it is difficult to account for cross-correlations among related assets when those assets trade continuously and simultaneously. Futures contracts are auctioned periodically and sequentially on the Tokyo Grain Exchange (TGE). Even though...

Mathematical programming models of “representative” farms are commonly used to evaluate policies such as input subsidies and output price supports. On canals in India, upstream farmers routinely use more irrigation water than allotted. In such circumstances, the programming model should...