On this picture blue line represents CPI and red line represents PPI from 2008. Black line is a gap between CPI and PPI(CPI - PPI).
Theoretically when CPI is higher than PPI, producers could have more margin. That means producers(suppliers) would make more money. And as you can see from 3Q of 2012 black line started to be greater than 0, which means CPI is higher than PPI.
this is a chart of "quaterly Korean GDP growth rate", change over previous quater. This shows Korean economy has been growing up from the bottom of 3Q of 2012. And it was same time when CPI is higher than PPI.
In 2009 you can see the same phenomenon.
I dont want to say this is perfect match, but would like to say it is somehow corelated.
