As predicted, the PPI of steel and iron has been declining

Two months ago we predicted the current fall in the producer price index of steel and iron in the fourth quarter of 2012: “The index of steel and iron will likely be falling in absolute terms in the fourth quarter of 2012 and the first quarter of 2013.”  Couple days ago the BLS reported various PPIs for November 2012. It’s time to revisit our prediction.  

Originally, we reported on the difference between the overall PPI and the PPI of steel and iron in 2008. Then we revisited the difference in 2010 and February 2012. We predicted the index of steel and iron to return to the long term trend, which express a higher rate of growth of the producer price index than that of steel and iron. Our general approach is based on the presence of long-term sustainable (linear and nonlinear) trends in the evolution of the CPI and PPI in the United States [1, 2]. The difference between various components of these indices is not a random one but is rather a predetermined process. Using these trends, one can predict consumer and producer price indices for select goods, services and commodities.  

Figure 1 compares the difference between the PPI and the index for iron and steel (101). The difference is characterized by the presence of a sharp decline between 2001 and 2008. Between 1985 and 2000, the curve fluctuates around the zero line, i.e. there was no linear trend in the absolute difference. In 2008, our main assumption was that the negative trend observed before 2008 should start transforming into a positive one after 2008. In Figure 1, the (expected) new trend is shown by green line. This trend suggests that the PPI grows faster than the index of steel and iron by approximately 2 units of index per year.  

Figure 2 demonstrates the most recent period and confirms that our prediction for 2012Q4 was correct – the difference has touched the green line. One may foresee the difference to fluctuate around the green line in the near future. The price of iron and steel will likely be declining.

 

Figure 1. The difference of the PPI and the index of steel and iron updated for the period between September 2012 and November 2012.

 

Figure 2. Same as in Figure 1 for the period between January 2005 and November 2012. Green line predicts the evolution of the difference after 2008. Red circles represent the difference between April 2009 and November 2012. The difference has been increasing during the reported period and reached the new trend (green).