I’d like to see a solid, peer reviewed study that states: in a normal, competitive market, business cost increases are not correlated with consumer price increases.
I mean, obviously they're going to be related. Even in a perfectly competitive environment, if everyone's costs increase then so will the going price. The operative question is whether these increased costs will be passed onto the consumer in their entirety, and that much isn't necessarily clear. If they do pass those costs on 100%, then it's a tacit admission that they weren't pricing in a profit-maximizing way before the cost increase.
Here in France, VAT is a tax collected by the business.
The myth is that a VAT increase (for instance, 7% => 10%, a couple of years ago) would shrink the business' margins : for 100€ paid by the customer, 93€ used to go to the business before the change, and only 90€ would go after the change.
Of course, and this is a massive surprise, all prices increased : the product now costs 110€, with 99€ going to the business and 11€ as VAT
So yeah, I'm pretty sure I know how my taxes work. That said, I can only speak about here in France, as I do not know how it works in other countries.