Liu Congmin, Cheng Jianhua, Wang Dehui
School of Mathematics, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
School of Economics, Liaoning University, Shenyang 110036, China.
Entropy (Basel). 2021 Jun 17;23(6):765. doi: 10.3390/e23060765.
This paper considers the periodic self-exciting threshold integer-valued autoregressive processes under a weaker condition in which the second moment is finite instead of the innovation distribution being given. The basic statistical properties of the model are discussed, the quasi-likelihood inference of the parameters is investigated, and the asymptotic behaviors of the estimators are obtained. Threshold estimates based on quasi-likelihood and least squares methods are given. Simulation studies evidence that the quasi-likelihood methods perform well with realistic sample sizes and may be superior to least squares and maximum likelihood methods. The practical application of the processes is illustrated by a time series dataset concerning the monthly counts of claimants collecting short-term disability benefits from the Workers' Compensation Board (WCB). In addition, the forecasting problem of this dataset is addressed.
本文在一个较弱条件下考虑周期自激阈值整值自回归过程,该条件是二阶矩有限而非给定创新分布。讨论了模型的基本统计性质,研究了参数的拟似然推断,并得到了估计量的渐近行为。给出了基于拟似然和最小二乘法的阈值估计。模拟研究表明,拟似然方法在实际样本量下表现良好,可能优于最小二乘法和最大似然法。通过一个关于从工人赔偿委员会(WCB)领取短期残疾福利的索赔人数月度计数的时间序列数据集说明了该过程的实际应用。此外,还解决了该数据集的预测问题。