Ristić Miroslav M, Weiß Christian H, Janjić Ana D
Int J Biostat. 2016 Nov 1;12(2). doi: 10.1515/ijb-2015-0051.
We present an integer-valued ARCH model which can be used for modeling time series of counts with under-, equi-, or overdispersion. The introduced model has a conditional binomial distribution, and it is shown to be strictly stationary and ergodic. The unknown parameters are estimated by three methods: conditional maximum likelihood, conditional least squares and maximum likelihood type penalty function estimation. The asymptotic distributions of the estimators are derived. A real application of the novel model to epidemic surveillance is briefly discussed. Finally, a generalization of the introduced model is considered by introducing an integer-valued GARCH model.
我们提出了一种整数值自回归条件异方差(ARCH)模型,该模型可用于对具有欠分散、等分散或过分散的计数时间序列进行建模。所引入的模型具有条件二项分布,并且已证明它是严格平稳且遍历的。未知参数通过三种方法进行估计:条件最大似然法、条件最小二乘法和最大似然型惩罚函数估计法。推导了估计量的渐近分布。简要讨论了该新模型在疫情监测中的实际应用。最后,通过引入整数值广义自回归条件异方差(GARCH)模型来考虑所引入模型的推广。