基于BP滤波的BDI周期性问题研究

国际干散货运输是开展海上贸易的主要运输方式。多年的实践证明国际干散货航运市场是一个具有明显周期性的产业,世界政治事件、经济波动、自然因素的周期性波动等都会影响国际干散货航运市场的行情,增加航运企业的经营风险。由于国际干散货运输市场具有一定的自我调节能力,即当运力超过运量时,运价下跌,导致运力减少,使运价上升,并趋于稳定。波罗的海运价指数（BDI）运价指数是根据严格、明确以及航运市场的规则计算出来,能够反映出全球干散货航运市场的运价水平,成为国际干散货航运市场发展和变化的＂晴雨表＂。目前国际上许多著名航运机构都对干散货航运市场周期性研究主要着眼于航运市场的定性分析以及统计资料的收集,采用定量模型来研究该问题则较为少见。本研究运用BP滤波实现趋势和循环要素的分离,获得国际干散货运输市场周期成分。研究表明,国际干散货运输市场中存在比较明显的长周期和短周期互现的态势。

Research of BDI Periodic Fluctuation based on BP Filter

International dry bulk cargo shipping market is one of the main transformational styles in sea trade. Many years＂ practice shows the periodical fluctuation is one of the most obvious characters in international dry bulk cargo shipping market. World political event, economic fluctuation and natural factors will influence the international dry bulk cargo shipping market and increase the business risks of shipping enterprises. International dry bulk cargo market has certain self- adjustment ability, namely when the total fleet surpasses the transportation amount, the freight index fall, cause total fleet to reduce which cause the freight index rise, and tends to stably. BDI computed through the strict definitely rules cam image the price level of international dry bulk cargo shipping market and becomes the weather glass of international dry bulk cargo market. Many famous international study institutions have many researches around the international dry bulk cargo shipping market. These reports mainly focus on the shipping market qualitative analysis as well as the statistical data collection, but using the quantitative model in periodicity of the bulk cargo market is rare. The BP filter method emphatically is chose to decompose BDI into cycle and tendency. The results show that in the dry bulk cargo shipping market long term periodical fluctuation stay with the short term periodical fluctuation.