Those of us who have been around for a while have noticed the steady reduction in the package size of many grocery items - without this being reflected in price. While this suggestion may be a little late in the day, I suggest that CHOICE is in the right position to commence a long-term (10 years to begin with?) review of this particular trend along with pricing trends.
Such a review would shed some light on the lengths to which manufacturers go to wring the reduce production costs without changing the cost to consumers.
The review would presumably focus on a representative ‘basket’ of items such as is already price compared, but in this instance would look at volume as well as price. The interest would be not so much in which grocery chain is cheapest, but in what happens to volume vs. price over time.