I love the friendly tone you have in a discussion.
It’s not the producers that’s going to pay for putting up and taking down the signs. It’s the stores and in the end the consumers.
Add to this the cost of having someone going around checking that the rules are followed.
Keeping track of whether there is a compare price or not on all items is much easier and cheaper.
So yeah, it’s a populist solution putting up signs for price increase only for goods that has shrunk and it seems extremely easy to circumvent if you want to.
Here’s how you circumvent it: Introduce a 750g, 900g and 1000g package of the product. 900g is more expensive per gram than the 1000g. Then you have a “shortage” on the 1000g package and some stores run out of it. There’s no shrinkflation here since the 900g package has been there all the time.
There’s a lot of money to make here so hiring a lawyer that finds every single loophole will be a good investment.
But yeah, you call the take braindead and watch the politicians, lawyers and producers laugh over a change that cost you, not them, money.