季节调整本底线与SARS对我国铁路客运量的影响

Assessment of SARS Influence on Railway Passenger Traffic Volume Based on SA Bottom Line

危机事件频繁发生会造成巨大经济损失,对其进行科学评估关系国家安全和灾后重建,具有重要意义。本文首先用TRAMO/SEATS季节调整模型,将月度时间序列数据分解成趋势-循环、季节和不规则因素,再根据异常值类型等对本底趋势线理论予以改进,最后对危机事件造成的经济损失进行定量评估。以我国2000年1月至2010年2月铁路客运为例,2003年SARS所造成铁路客运量的损失评估为重点。结果表明,模型通过各项检验,对铁路客运量的拟合和分解效果非常好;根据SARS造成的更新异常值,改进的本底趋势线更科学;SARS共造成铁路客运量损失1.4654亿人次,以往研究中的损失评估偏低;2003年3～4月危机开始显现,5～6月危机全面爆发并达到巅峰,7～11月是衰减和恢复期,SARS危机对铁路客运量的影响持续9个月。

In recent years, frequent emergence of public crises has resulted in generation of huge losses, so an accurate assessment of such crises is essential for national security and conseguential reconstruction. In this paper, the monthly data time series are decomposed into the trend-cycle and seasonal and irregular fluctuations by the TRAMO/SEATS seasonal adjustment model. The theory of the bottom trend line is improved according to the types of exceptional values and the losses caused by crises are assessed guantitctively. Railway passenger traffic from Jan 2000 to Feb 2010 is assessed with the 2003 SARS losses as the major point. The results show as follows, The model fits and decomposes the data very well and passes all tests, the improved bottom trend line is more scientific; SARS in 2003 caused a total loss of 0. 14654 billion railway passenger journeys, thus verifying previous studies underestimated the losses in 2003, the SARS crisis began to emerge from March to April, broke out in an all-round way and reach its peak from May to June and attenuated and recovered from July to November. The SARS crisis affected the railway passenger traffic volume over a period of 9 months.