Commonly used tests to assess evidence for the absence of autocorrelation in a univariate time series or serial cross-correlation between time series rely on procedures whose validity holds for i.i.d. data. When the series are not i.i.d., the size of correlogram and cumulative Ljung-Box tests...

We consider the long-memory and leverage properties of a model for the conditional variance V of an observable stationary sequence X, where V is the square of an inhomogeneous linear combination of X, s lt; t, with square summable weights b. This model, which we call linear autoregressive...