Table 4. Results of unit root test for the log-level and log-differenced data

Capesize	Log-level	t-value	−0.045
	Log-level	p-value	0.667
	Log-differenced	t-value	−14.742
	Log-differenced	p-value	0.000***
Panamax	Log-level	t-value	0.318
	Log-level	p-value	0.777
	Log-differenced	t-value	−10.441
	Log-differenced	p-value	0.000***

Note: 1) *, **, *** indicate significance at 10%, 5%, 1% level, respectively.
2) The t-statistic refers to the Augmented Dickey-Fuller test statistic. Refer to Dickey and Fuller (1979, 1981).
3) For the log-level and log-differenced data, the test does not have a constant or trend.
4) The p-value implies MacKinnon’s (1996) one-sided p-value.
5) The values less than 1/1000 are dropped.