Table 5.

Results of long memory tests after COVID-19 break.

Data analyzed	Sample size (weeks)	Model Selected	d	Std. Error	Interval	I(d)
Long memory test
Bloomberg Commodity Index	22	ARFIMA (0, d, 0)	1.09	0.1841467	[0.79, 1.39]	I(1)
Baltic Dry Index	22	ARFIMA (0, d, 0)	0.77	0.238872	[0.38, 1.16]	I(1)
Harpex Shipping Index	22	ARFIMA (0, d, 0)	1.32	0.142127	[1.09, 1.55]	I(d > 1)
Shanghai Shipping Exchange Containerized Freight Index	22	ARFIMA (0, d, 0)	1.22	0.1203744	[0.91, 1.53]	I(1)