This chapter evaluates the most important theoretical developments in ARCH type modeling of time-varying conditional variances. The coverage include the specification of univariate parametric ARCH models, general inference procedures, conditions for stationarity and ergodicity, continuous time...

The realization among econometricians and applied economists that seasonal variation in many time series is often larger and less regular than has been supposed, has recently led to an increased interest in seriously modelling seasonality. The relative size of seasonal variation also means that...