[stockpirate]

Interesting that you signed up to post an answer. I read the link and I see nothing that states they look at decreased portion size at the same price.

Ground beef is about $5.00 a pound, I used to pay that for steak.

[pinqy27]

But why would you think that the thousands of people who have calculated the CPI over the hundred years it's been around would not recognize that you have to adjust for quality changes like change in package size? http://www.bls.gov/cpi/cpifaq.htm#Question_8
"If the selected item is no longer available, or if there have been changes in the quality or quantity (for example, eggs sold in packages of ten when they previously were sold by the dozen) of the good or service since the last time prices were collected, the economic assistant selects a new item or records the quality change in the current item.