more about gas vs. diesel

Image by Cool Pixels via FlickrNormand Miron was kind enough to provide this link; the discussion of gas and diesel prices is in the comments:

• Diesel demand is relatively constant, while gas demand fluctuates. This means that over the short term fuel companies can raise prices incrementally without losing business.
  
• American use of diesel and gas are out of balance relative to the ratio in which they are typically produced, and as a result there's a shortage of diesel refining capacity without there being a corresponding shortage of gasoline refining capacity.

So there you go: some people blame greed, others blame (other) market forces.