Table 1.

Descriptive statistics of metal prices

Variable	Mean US dollars	Standard deviation	Minimum US dollars	Maximum US dollars
Aluminum	1778.47	411.35	1139.93	2639.86
Copper	4517.85	2518.27	1560.29	9296.16
Lead	1325.78	771.57	407.34	2579.12
Iron	54.22	50.62	11.45	167.79
Nickel	12,838.74	7073.47	4623.59	37,135.84
Tin	12,526.41	7809.72	4061.00	31,747.72
Zinc	1731.85	762.77	778.90	3266.18