Incorrect waist size

Smaller than they should be -- I've ordered these exact brand, model and size at several other retailers in the past, with no issues. But even though the Amazon product showed the same information, including the same product numbers on the actual tags, their size is definitely not the same. I ordered the 40x38, but when I compare these to supposedly identical jeans purchased in the past, these Amazon ones are about 2-3 inches smaller at the waist.Other than that they are good jeans, but for online clothing sales it's imperative to carry accurate sizes since people can't try them on in advance...