Coal Price Forecasting and Structural Analysis in China

Table 1

ADF unit root test results.

Variable	ADF test statistic	Prob.	1% level	5% level	10% level	Conclusion
LOGF						Nonstationary
DLOGF						Stationary
PP						Nonstationary
DPP						Stationary
LOGP						Nonstationary
DLOGP						Stationary
LOGS						Stationary
DLOGS						Stationary
LOGSS						Stationary
DLOGSS						Stationary
LOGW						Nonstationary
DLOGW						Stationary

Notes: D represents the first difference of variables. indicates 10% significant level. indicates 5% significant level. indicates 1% significant level.