I've been seeing this more in the news lately, but I came across a new example of this today as I was grocery shopping. It's a sneaky price hike in which instead of raising prices, they shrink the container size.
The example is a bottle of Ragu pasta sauce. From the picture, can you tell which is bigger? Two bottles of Ragu Pasta Sauce
A closeup of the weight labels reveals the reduction. closeup showing the weights
As you can see, the weight has shrunk from 26oz to 24oz which is a reduction of 7.70%. The price is the same as before. They are still selling the 26oz bottles, but these probably won't last much longer.
If you have other examples of this stealth price increase, please leave a comment. I'm sure we'll be seeing a lot more of this if the recent energy and food inflation continues.