Modelling the volatility of the tanker freight market based on improved empirical mode decomposition

In this article, a method based on empirical mode decomposition (EMD) and BEKK–Multivariate GARCH (MVGARCH) is developed to analyse the volatility of the tanker freight market. First, the initial time series of tanker freight rates is decomposed into several independent intrinsic mode functions (IMFs). Next, the IMFs are composed as three components by an improved EMD: the long-term trend time series that represents the benchmark freight rates of the tanker freight market, the high-frequency time series that reflects the short-term supply–demand relation and the low-frequency time series caused by extreme events. Based on the results of EMD, the volatility spillover effects between the freight rates of Aframax, Suezmax and Very Large Crude Carrier (VLCC) markets are tested by the BEKK–MVGARCH model. The results indicate that there are volatility spillover effects between the reconstructed components, although the volatility spillover effects between the original freight series are not significant. The improved EMD method contributes to the retention of the economic characteristics of the original time series, thereby providing a vital approach for tanker freight market analysis. Furthermore, the potential volatility spillover among different sub-markets can be investigated through the integration of EMD and the BEKK–MVGARCH.     

世界铁矿资源分布对我国钢铁工业发展的影响

钢铁工业是国民经济的基础性产业。随着我国钢铁产量的不断提高,对铁矿石的需求也在逐年增加,尽管我国铁矿石产量一直大幅度提高,但仍不能满足我国钢铁工业发展的需要,使得进口铁矿石的数量必须不断增加．我国也因此成为世界上进口铁矿石最多的国家。而世界铁矿资源分布比较集中,对我国钢铁工业的发展有直接的影响。根据铁矿资源的分布情况,分析我国钢铁工业在原料供需方面所面临的问题,并提出一些相应的对策。     

Cross-sectional and time-series momentum returns and market dynamics: evidence from Japan

We test the behavioural theories of overconfidence and underreaction on cross-sectional (CS) and time-series (TS) momentum returns in the Japanese stock markets. Both CS and TS momentum returns are large and significant when the market continues in the same state and turns into losses when the market transitions to another state, consistent with the overconfidence but not the underreaction model. We find that TS conditional momentum returns exceed conditional CS momentum returns because of its active position since TS takes a net long (short) position following UP (DN) markets while CS is a zero-cost strategy irrespective of the market state. Finally, we find no relation between idiosyncratic volatility (IV) and momentum returns which is not supportive of either the overconfidence or underreaction model but implies that IV is not a significant limit to arbitrage in Japan.