Computing is the extreme example of this phenomenon. Economists don't in general have a great way to handle this issue, because it varies so greatly across indu

Computing is the extreme example of this phenomenon. Economists don't in general have a great way to handle this issue, because it varies so greatly across industries. A loaf of bread is just about the same as it's always been. Oh wait, maybe wonderbread is worse and artisinal ciabatta is better? Sometimes economists like to create some aggregate measure of increasing consumer choice by counting the number of SKUs available in a store. Big box stores pushing out Mom & Pop made that awkward. Now Amazon makes it tougher still. Back in grad school, I was not aware of any consensus on the topic. I haven't kept up with it since. One technique is to focus your research on products that are largely stable in quality. For example, wine glasses. Not plastic ones, but glass or crystal. They've got a fairly large distribution in "quality" or at least in price and yet had a fairly stable range of quality since the 1950s.