A wide range of tests for heteroskedasticity have been proposed in the econometric and statistics literatures. Although a few exact homoskedasticity tests are available, the commonly employed procedures are quite generally based on asymptotic approximations which may not provide good size...

A wide range of tests for heteroskedasticity have been proposed in the econometric and statistics literature. Although a few exact homoskedasticity tests are available, the commonly employed procedures are quite generally based on asymptotic approximations which may not provide good size control...

Empirical research on oil price dynamics for modeling and forecasting purposes has brought forth several unsettled issues. Indeed, statistical support is claimed for various models of price paths, yet many of the competing models differ importantly with respect to their fundamental temporal...