基于平衡轮换样本调查的季节调整方法研究

传统季节调整方法对时间序列数据进行季节调整时,往往假定误差项为白噪声,不考虑其序列相关关系。为了进行更准确地季节调整分析,本文从连续性抽样调查的角度出发,研究基于平衡轮换样本调查的抽样误差对季节调整的影响,建立一般化的季节调整模型,利用卡尔曼滤波进行参数估计,并从预测误差、误差方差等角度评价模型精度。最后以中国城镇住户调查采用的12～0平衡轮换模式为例,对考虑抽样误差结构特征的季节调整模型进行实证分析,验证这套季节调整方法的有效性。     

季节调整方法在CPI指数中的应用

文章首先对季节调整方法的发展及应用进行了说明,着重介绍了国际上使用最广泛的两种方法:X-12-ARIMA和TRAMO/SEATS;然后用X-12-ARIMA方法对我国居民消费价格指数序列进行了季节调整,探测了交易日、闰年、异常值和春节对CPI指数的影响,比较了三种季节调整模型之间的优劣并进行调整,得出了我国CPI指数只受春节因素的影响的结论,相应的最优模型也是春节效应模型;最后用这种模型对我国CPI指数进行季节调整,分离出趋势成分、季节成分和不规则成分,得到了最终的季节调整序列。     

我国CPI季节调整模型预测

文章基于考虑春节效应的X-12-ARIMA季节调整模型,对我国2002年1月至2013年12月的CPI序列月度数据进行季节调整,并进行季节波动性分析及短期预测.实证结果表明:我国的CPI变动存在明显的季节性特征,春节效应对其有显著影响;CPI序列的短期波动主要是受季节性成分影响,而长期波动主要受趋势-循环成分影响;利用该模型进行短期预测效果较好,预测误差绝对值控制在1.5％之内.     

基于季节调整技术的我国物价波动实证研究

 本文首先对季节调整方法的发展及应用进行说明,并对X-12-ARIMA和TRAMO/SEATS进行方法与实证比较,得出这两种方法调整效果基本相同;其次使用X-12-ARIMA方法对我国CPI时间序列数据做了实证研究,分离出最终趋势成分、季节成分等;然后通过PBC版X-12-ARIMA分理处时间序列中的春节因素;最后通过调整后的CPI序列进行短期预测,并对其展开了一定的分析讨论。     

环比增长率测算季节调整模型的评价和选择

季节调整使子年度数据可比,有利于环比增长率测算和经济监测。国际上季节调整模型众多,模型选择是季节调整的首要任务。以国际常用的X-12-ARIMA和TRAMO/SEATS模型的选择为目标、以两模型理论差异分析为基础、以中国2001—2010年的月度CPI数据为样本,通过谱分析方法检验剩余季节性、幂等、平滑间距和修正历史等方法检验模型稳定性、通过Friedman和Kruskal-Wallis等非参数方法检验季节稳定性,得出模型之间更具体的差异,为满足实践需要进行模型选择提供科学依据。     

季节调整新方法及其原理研究

本文的主要工作是从频域的角度对季节调整中“季节滤子”的设计及估计问题进行研究。通过将直接信号提取（DSEF）方法引入到季节调整的应用之中,突破现有季节调整方法中仅能处理季度或月度数据的限制,且该方法下季节调整后的序列是理论季节调整后序列的“均方误差”最小估计。将DSEF方法应用于对中国季度进出口总额序列的季节调整分析中。分析结果显示,相比于X-11和SEATS方法,DSEF方法季节调整结果的离差较小且稳健性较好。     

我国铁路客运量的季节时间序列模型

针对季节调整方法如X-11等调整结果不利于解释,及其方法本身没有考虑我国像春节等季节性特点的不足,文章建立起一般的季节时间序列模型,另外,针对季节周期的主观诊断,文章建立起辅助回归模型,较为客观的诊断时间序列的季节周期。结合我国铁路客运量的实证分析,预测结果表明:未来10月铁路客流量较大,相反,11月和12月客运量较小,这点和历史数据的特征十分类似,说明建立的模型较合适。     

Census X12季节调整下的黑龙江零售品销售总额的预测研究

文章在对季节调整方法进行理论总结的基础上,采取Census X12季节调整办法对黑龙江零售品销售总额序列(2003～2008)进行剥离,得到长期趋势TC和季节因素S,并计算出季节因素的影响系数—季节指数;对长期趋势TC序列进行时间序列回归预测季节调整后的2009年1～12月值,再运用季节指数得到2009年1～12月的总序列预测结果;运用配对检验预测得到的2009年1～7月份数据与实际观测值在95%显著性水平下不存在显著差异。     

季节调整方法综述及比较

一、前言所谓季节调整,就是将某一统计指标的时间序列中的季节性因素和偶然性因素剔除,从而使经过季节调整的时间序列能够较为准确地反映出社会经济运行基本态势。早在20世纪的上半叶人们就开始了从时间序列中分解季节因素、调整季节变动的尝试。季节调整的问题首先是由美国经济学家1919年提出的,此后,有关季节调整的方法不断的出现和改进。1931年麦考利(Macauley)提出了用移动平均比率法进行季节调整,成为季节调整方法的基础。1954年Shiskin在美国普查局首先开发了在计算机上运行的程序对时间序列进行季节调整,称为X1,此后,季节调整的方…     

异方差帕克检验方法的改进

围绕传统的帕克检验方法展开研究,针对该方法在对多元线性回归模型进行异方差检验时工作量大、计算繁琐、异方差模型不够准确这一系列问题,提出运用主成分的思想,将得到的所有综合指标建立异方差模型,并对不同形式的数据条件进行研究,根据系数的显著性检验,给出了一种新的异方差检验方法。模拟数据和实例论证表明该检验方法更为快捷准确。     

Maximum entropy extreme‐value seasonal adjustment

Some economic series in small economies exhibit meagre (i.e. non‐positive) values, as well as seasonal extremes. For example, agricultural variables in countries with a distinct growing season may exhibit both of these features. Multiplicative seasonal adjustment typically utilises a logarithmic transformation, but the meagre values make this impossible, while the extremes engender huge distortions that render seasonal adjustments unacceptable. To account for these features, we propose a new method of extreme‐value adjustment based on the maximum entropy principle, which results in replacement of the meagre values and extremes by optimal projections that utilise information from the available time series dynamics. This facilitates multiplicative seasonal adjustment. The method is illustrated in the New Zealand agricultural series.     

Dynamic structural models with covariates for short-term forecasting of time series with complex seasonal patterns

This work presents a framework of dynamic structural models with covariates for short-term forecasting of time series with complex seasonal patterns. The framework is based on the multiple sources of randomness formulation. A noise model is formulated to allow the incorporation of randomness into the seasonal component and to propagate this same randomness in the coefficients of the variant trigonometric terms over time. A unique, recursive and systematic computational procedure based on the maximum likelihood estimation under the hypothesis of Gaussian errors is introduced. The referred procedure combines the Kalman filter with recursive adjustment of the covariance matrices and the selection method of harmonics number in the trigonometric terms. A key feature of this method is that it allows estimating not only the states of the system but also allows obtaining the standard errors of the estimated parameters and the prediction intervals. In addition, this work also presents a non-parametric bootstrap approach to improve the forecasting method based on Kalman filter recursions. The proposed framework is empirically explored with two real time series.     

On the nearly nonstationary seasonal time series

A time series is said to be nearly nonstationary if some of its characteristic roots are close to the unit circle. For a seasonal time series, such a notion of near-nonstationarity is studied in a double-array setting. This approach not only furnishes a natural transition between stationarity and nonstationarity, but also unifies the corresponding asymptotic theories in a seasonal-time-series context. The general theory is expressed in terms of functionals of independent diffusion processes. The asymptotic results have applications to estimation and testing in a nearly nonstationary situation and serve as a useful alternative to the common practice of seasonal adjustment.     

Identification of seasonal arima models using a filtering method

This paper proposes an identification method of ARIMA models for seasonal time series using an intermediary model and a filtering method. This method is found to be useful when conventional methods, such as using sample ACF and PACF, fail to reveal a clear-cut model. This filtering identification method is also found to be particularly effective when a seasonal time series is subjected to calendar variations, moving-holiday effects, and interventions.     

Assessing direct and indirect seasonal decomposition in state space

The problem of whether seasonal decomposition should be used prior to or after aggregation of time series is quite old. We tackle the problem by using a state-space representation and the variance/covariance structure of a simplified one-component model. The variances of the estimated components in a two-series system are compared for direct and indirect approaches and also to a multivariate method. The covariance structure between the two time series is important for the relative efficiency. Indirect estimation is always best when the series are independent, but when the series or the measurement errors are negatively correlated, direct estimation may be much better in the above sense. Some covariance structures indicate that direct estimation should be used while others indicate that an indirect approach is more efficient. Signal-to-noise ratios and relative variances are used for inference.     

The effects of additive outliers on the seasonal KPSS test: a Monte Carlo analysis

This article builds on the test proposed by Lyhagen [The seasonal KPSS statistic, Econom. Bull. 3 (2006), pp. 1–9] for seasonal time series and having the null hypothesis of level stationarity against the alternative of unit root behaviour at some or all of the zero and seasonal frequencies. This new test is qualified as seasonal-frequency Kwiatkowski–Phillips–Schmidt–Shin (KPSS) test and it is not originally supported by a regression framework.

The purpose of this paper is twofold. Firstly, we propose a model-based regression method and provide a clear illustration of Lyhagen's test and we establish its asymptotic theory in the time domain. Secondly, we use the Monte Carlo method to study the finite-sample performance of the seasonal KPSS test in the presence of additive outliers. Our simulation analysis shows that this test is robust to the magnitude and the number of outliers and the statistical results obtained cast an overall good performance of the test finite-sample properties.     

A note on spurious regression in seasonal time series

This paper considers spurious regression between two different types of seasonal time series: one with a deterministic seasonal component and the other with a stochastic seasonal component. When one type of seasonal time series is regressed on the other type and they are independent of each other, the phenomenon of spurious regression occurs. Asymptotic properties of the regression coefficient estimator and the associated regression ‘t-ratio’ are studied. A Monte Carlo simulation study is conducted to confirm the phenomenon of spurious regression and spurious rejection of seasonal cointegration for finite samples.     

Estimation for seasonal fractional ARIMA with stable innovations via the empirical characteristic function method

Seasonal fractional ARIMA (ARFISMA) model with infinite variance innovations is used in the analysis of seasonal long-memory time series with large fluctuations (heavy-tailed distributions). Two methods, which are the empirical characteristic function (ECF) procedure developed by Knight and Yu [The empirical characteristic function in time series estimation. Econometric Theory. 2002;18:691–721] and the Two-Step method (TSM) are proposed to estimate the parameters of stable ARFISMA model. The ECF method estimates simultaneously all the parameters, while the TSM considers in the first step the Markov Chains Monte Carlo–Whittle approach introduced by Ndongo et al. [Estimation of long-memory parameters for seasonal fractional ARIMA with stable innovations. Stat Methodol. 2010;7:141–151], combined with the maximum likelihood estimation method developed by Alvarez and Olivares [Méthodes d'estimation pour des lois stables avec des applications en finance. Journal de la Société Française de Statistique. 2005;1(4):23–54] in the second step. Monte Carlo simulations are also used to evaluate the finite sample performance of these estimation techniques.     

Issues Involved With the Seasonal Adjustment of Economic Time Series

In the first part of this article, we briefly review the history of seasonal adjustment and statistical time series analysis in order to understand why seasonal adjustment methods have evolved into their present form. This review provides insight into some of the problems that must be addressed by seasonal adjustment procedures and points out that advances in modem time series analysis raise the question of whether seasonal adjustment should be performed at all. This in turn leads to a discussion in the second part of issues involved in seasonal adjustment. We state our opinions about the issues raised and review some of the work of other authors. First, we comment on reasons that have been given for doing seasonal adjustment and suggest a new possible justification. We then emphasize the need to define precisely the seasonal and nonseasonal components and offer our definitions. Finally, we discuss criteria for evaluating seasonal adjustments. We contend that proposed criteria based on empirical comparisons of estimated components are of little value and suggest that seasonal adjustment methods should be evaluated based on whether they are consistent with the information in the observed data. This idea is illustrated with an example.     

Issues Involved With the Seasonal Adjustment of Economic Time Series

In the first part of this article, we briefly review the history of seasonal adjustment and statistical time series analysis in order to understand why seasonal adjustment methods have evolved into their present form. This review provides insight into some of the problems that must be addressed by seasonal adjustment procedures and points out that advances in modern time series analysis raise the question of whether seasonal adjustment should be performed at all. This in turn leads to a discussion in the second part of issues invloved in seasonal adjustment. We state our opinions about the issues raised and renew some of the work of our authors. First, we comment on reasons that have been given for doing seasonal adjustment and suggest a new possible justification. We then emphasize the need to define precisely the seasonal and nonseasonal components and offer our definitions. Finally, we discuss our criteria for evaluating seasonal adjustments. We contend that proposed criteria based on empirical comparisons of estimated components are of little value and suggest that seasonal adjustment methods should be evaluated based on whether they are consistent with the information in the observed data. This idea is illustrated with an example.