Forecasts are of great importance and widely used in economics and finance. Quite simply, good forecasts lead to good decisions. The importance of forecast evaluation and combination techniques follows immediately—forecast users naturally have a keen interest in monitoring and improving...

Many economic and financial time series have been found to exhibit dynamics in variance; that is, the second moment of the time series innovations varies over time. Many possible model specifications are available to capture this phenomena, but to date, the class of models most widely used are...