The Scaling Behavior of Bulk Freight Rate Volatility

This article reports on a study that investigated bulk freight rate volatility, specifically scaling behavior. The authors note that freight rate volatility characteristics drew attention after 2008, due to the effect of worldwide credit crunch and a concomitant slowdown in marine transportation. The authors studied the long memory feature of the bulk freight rate index and determined that scaling behavior was present. However, this scaling behavior can be eliminated after using a nonlinear noise reduction technique, therefore high-frequency noise is determined to be the cause of scaling behavior. The authors also compared long memory features between different vessel sizes: Supramax, Panamax and Capesize bulk carriers. Similar results were found, including disappearance of the scaling behavior after noise reduction. The authors note that load capacity is one of the short-term external factors which result in high frequency noises in freight rate index time series. The authors conclude with a brief discussion of the impact of these findings for advisors consulting on risk management.