Have you noticed how the grocery store almost always used different units for comparable products? For example, the tag might be $/oz for Kellogg's but $/lb for General Mills. And that is sometimes with tiny products that have no business being in dollars per pound.

I think they are purposely trying to make it more difficult to compare.

Same with the energy label of food. In the metric system:

Portion sizes of 65 gram in a 90 gram container. Then the label shows for 10 gram, portion size, and 100 grams. But not the actual weight of the container!

I mean, what 'portion' consists of 65/90th of a container? They know full well that the actual portion people consume $PRODUCT in is what is in the box.

A recent change in US nutrition labels is the serving size should be more realistic so they update the numbers to match consumer behavior. The other thing is consumption is influenced by container size. People tend to drink entire bottles of soda regardless of size so labeling should reflect that.

https://www.fda.gov/food/food-labeling-nutrition/changes-nut...

Still not great leaving it up to manufacturers. Would have loved if it was a flat XX/100grams plus an additional column of XX/package.

I mean, obviously the best thing is:

1gram, 100gram, container size.

That way: you always know the exact amount you're actually buying, + it's easy to calculate if you consume less than the container, either by nx the amount of 1gram or nx100 gram of the product. Nothing else really makes sense, for any reason.

I don't have a specific example handy, but some appliance manufacturers will adjust the model number per-store (a washing machine will be model XYZ at Home Depot, model ABC at Best Buy) to make it more difficult to compare.

I see this most commonly with fruit:

  Blueberries, $j/lb
  Organic Blueberries, $k/pint

It seems very intentional to me.

Hm, no not I have not seen that, at least not that I can remember. Fortunately since I carry a computer in my pocket I can easily calculate it as needed.

This is one of the reasons I love Trader Joe’s. No comparison shopping. If you want granola just pick the flavor that looks best.

General question, can the concentration of items like dish soap/shampoo change? There are times I feel like I can wash a lot more with less soap using the same brand, size, etc. How would we as the consumer be able to detect if products get diluted, when it's sold in the same packaging. The $/oz remains the same, but the product is inferior than previously.

I don't know the answer to your question, but consider this related question. "Do some companies feel financially incentivised to do exactly this?".

I bought a jar of marinara sauce a couple weeks ago. I just opened it and used some of it. Much more watery than I'm used to. I didn't check the nutritional label but marinara sauce is a mix of solids and water. So it seems like they've lowered costs by decreasing the solids.

Same thing sometimes happen when you buy uncooked ham or turkey: they often inject it with a lot of salt water ("up to 8% brine solution") to increase the weight without increasing the actual product.

I try to do this as well but I still have no idea how to shop for pickles. They're sold by the fluid ounce but it's not clear how much of that weight is pickling liquid and how much is the pickles.

Buy the ones that taste better (to you).