Does Weight matter? A Statistical analysis of the SSY Capesize index

This paper examines the statistical properties of 19 dry cargo rate series, which are used in the construction of index numbers measuring dry cargo market conditions for Capesize vessels. It is shown that the series are extremely highly correlated. They are also non-stationary. The presence of cointegration is established. It is argued that this implies that rebasing the index numbers using different weights makes little difference to the information derived from the index itself, because of the high correlation between the series and the presence of cointegration. Changing the weighting structure does not alter the information derived from the index in any material way because of these properties.