[ImPostingOnHN]

They have to alter the packaging to account for the changes. They can either do so in a way that makes apparent to the customers that they're receiving less value for their money, making sure they're aware of it, or they can do so in a way that attempts to deceive consumers and hide this information.

An example of messaging for the former is described in the quote you quoted. Another would be to use different-looking packaging, to indicate that it is not what it was before. If a consumer will still buy the item when properly informed of the lower value, then this apparent labeling should not have any effect on sales. If it does, it means the information hiding was material, which makes it bad.

tl;dr: companies hide this information because being deceptive increases sales, if it didn't, they wouldn't

[robertlagrant]

> If a consumer will still buy the item when properly informed of the lower value, then this apparent labeling should not have any effect on sales.

If it looks different, consumers might not know it's the same thing just smaller. E.g. if I buy a box of Celebrations, I know what each little sweet is because it shares the same packaging as its normal-sized equivalents. I know it's smaller because...it's smaller.

[ImPostingOnHN]

If it doesn't look different, customers might not know it's a different product than before due to the quantity change, and won't be prompted to investigate further.

Indeed, if the packaging is the same except for the quantity labels, then you don't, in fact, know it's smaller, because both the quantity change and the packaging change has been calculated to hide that fact from you. That's the problem being solved here.

With a proper packaging change, on the other hand, your confusion is resolved within seconds, when you read the packaging, which can include whatever explanatory info the manufacturer decides to put there. And if it's not resolved? The manufacturer should do better to explain.