**Table 3: Real commodity** **<u>price decomposition, 1970-2020</u>**

||<br>**Share**<br>|<br>**of varianc**<br><br>|**p **<br>**e explain**<br>|<br>**ed by**<br>|**p,**<br>**Number**<br>|<br>**of cycles**<br>|<br>|P<br>t|
|---|---|---|---|---|---|---|---|---|
||Pt|TPt<br>[8−20]|TPt<br>[2−8]|STt|TPt<br>[8−20]|TPt<br>[2−8]|_β_|_RMSE_|
|**ENERGY**|||||||||
|Coal [**4.6**]|0.30|0.47|0.21|0.03|3|11|0.43|5.31|
|Crude oil [**84.6**]|0.24|0.60|0.12|0.04|2|12|1.02|7.65|
|Natural gas [**10.8**]|0.15|0.72|0.10|0.03|2|11|0.57|2.50|
|**Average**|**0.24**|**0.60**|**0.12**|**0.04**|**2**|**11**|**0.95**|**6.99**|
|**BASE METALS**|||||||||
|Aluminum [**312.9**]|0.58|0.19|0.20|0.04|4|10|-0.14|0.64|
|Copper [**47.4**]|0.47|0.31|0.20|0.03|3|9|-0.80|3.31|
|<br>Lead [**2.2**]|0.55|0.26|0.16|0.03|3|8|-0.54|4.75|
|<br>Nickel [**9.9**]|0.18|0.44|0.34|0.05|3|11|-0.78|1.63|
|<br>Tin [**2.6**]|0.71|0.22|0.06|0.01|3|12|0.05|4.38|
|Zinc [**5.0**]|0.24|0.24|0.48|0.05|3|8|-0.09|2.08|
|<br>**Average**|**0.47**|**0.27**|**0.22**|**0.03**|**3**|**10**|**-0.52**|**2.46**|
|**PRECIOUS METALS**|||||||||
|Gold [**77.8**]|0.62|0.27|0.09|0.02|3|8|1.28|5.38|
|Platinum [**18.9**]|0.19|0.53|0.24|0.05|3|11|-0.22|1.85|
|<br>Silver [**3.3**]|0.45|0.39|0.14|0.03|3|11|0.27|13.47|
|**Average**|**0.53**|**0.33**|**0.12**|**0.02**|**3**|**10**|**0.96**|**4.98**|
|**FERTILIZERS**|||||||||
|Phosphate [**16.9**]|0.34|0.33|0.26|0.07|3|9|-0.40|6.48|
|<br>Potassium [**20.1**]|0.33|0.47|0.17|0.03|3|10|-0.46|3.43|
|<br>TSP [**21.7**]|0.33|0.26|0.35|0.06|4|9|-0.52|3.91|
|<br>Urea [**41.3**]|0.21|0.43|0.22|0.14|3|12|-0.02|4.44|
|<br>**Average**|**0.28**|**0.39**|**0.25**|**0.09**|**3**|**10**|**-0.28**|**4.47**|
|<br>**ANNUAL AGRICULTURE**|||||||||
|Cotton [**8.5**]|0.80|0.07|0.11|0.02|3|13|-0.07|9.00|
|Maize [**20.5**]|0.70|0.15|0.11|0.04|3|10|-0.50|3.55|
|Rice [**15.2**]|0.63|0.18|0.14|0.05|3|9|-0.43|3.29|
|Soybean meal [**29.0**]|0.68|0.11|0.16|0.05|3|10|-0.48|3.48|
|Soybean oil [**14.3**]|0.66|0.15|0.15|0.03|3|11|-0.72|3.15|
|<br>Wheat [**12.5**]|0.62|0.17|0.15|0.07|3|9|-0.42|2.60|
|**Average**|**0.68**|**0.14**|**0.14**|**0.04**|**3**|**10**|**-0.47**|**3.78**|
|<br>**PERENNIAL AGRICULTU**|**RE**||||||||
|Cocoa [**25.6**]|0.66|0.23|0.10|0.01|3|11|0.03|15.41|
|<br>Coffee Arabica [**15.7**]|0.60|0.24|0.13|0.03|3|14|0.22|10.38|
|<br>Coffee Robusta [**15.7**]|0.74|0.18|0.06|0.02|3|13|0.42|15.86|
|<br>Natural Rubber [**30.6**]|0.29|0.45|0.23|0.03|3|10|-0.36|17.39|
|Tea [**12.4**]|0.77|0.08|0.12|0.04|3|13|-0.17|9.47|
|<br>**Average**<br>|**0.56**|**0.27**|**0.14**|**0.02**|**_3_**|**_12_**|**-0.03**|**14.56**|
|**_ALL AVERAGE_**|**_0.46_**|**_0.33_**|**_0.17_**|**_0.04_**|**_3_**|**_11_**|**_0.10_**|**_6.21_**|
|<br>**Notes**: The numbers in the<br>|<br>square<br>|<br>brackets of<br>|<br>the first c<br><br>|<br>olumn r<br><br>|<br>epresent w<br>|eights and<br>|<br>add to 1<br>|<br>00 for each<br>|
|commodity group, subject<br>nent, medium-term cycle,<br>ject to rounding. For exam<br>|to round<br>business<br>ple, crud<br>|ing errors.<br>cycle, and<br>e oil’s sha<br>|Pt,TPt<br>[8−<br>short-term<br>res are: 0.2<br>|20],TPt<br>[2<br>fluctua<br>4 + 0.60<br>|−8], andSTt <br>tions, the s<br>+ 0.12 + 0.0<br>|denote the<br>hares of wh<br>4 = 1. The<br>|perman<br>ich add<br>penultim<br>|ent compo-<br>to 100, sub-<br>ate column<br>|
|reports the parameter estim|ate of_β_|from a reg|ressions of|ll(Pt|)on a time|trend. The|last colu|mn reports|
|the Root Mean Square Erro|r (RMSE|) from the|same regre|ssion. T|he last row|(“ALL AV|ERAGE”|) shows the|
|arithmetic average over th|e five gro|up-weight|ed averag|es.|||||

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