If two accounts show different prices, it proves the pricing algorithm isn’t standard, but if they show the same price, it doesn’t prove that there are never situations where the pricing algorithm is predatory. It’s hard to prove a negative.

> if they show the same price, it doesn’t prove that there are never situations where the pricing algorithm is predatory. It’s hard to prove a negative.

That makes no sense, that's not what unfalsifiable means. By your logic even conservation of momentum is unfalsifiable, since you can't prove it holds in every situation. In fact I'm struggling to think of a single scientific theory that would be falsifiable by your definition.

Conservation of momentum is falsifiable because you could construct an experiment that where the expected movement based on the theory might not be observed, in which case the theory would be falsified.

Perhaps what you are getting at is that scientific theories can not be "known true" through experiments. This is correct. Theories can only be strengthened by experiments. It is not uncommon for theories long-believed true to be falsified later, despite extensive experimentation supporting them. Conservation of momentum, for example, doesn't apply when you zoom out far enough (i.e. general relativity).

The proposition that is unfalsifiable in this case is this: "Uber sometimes charges different rates based on if the user has credits." An experiment where the same rate is shown would not falsify this proposition, nor obviously would an experiment where a different rate is shown.

> Conservation of momentum is falsifiable because you could construct an experiment that where the expected movement based on the theory might not be observed, in which case the theory would be falsified.

No. That would only prove something about your specific time/location/instance of the experiment. It doesn't prove that the law holds in all time/space/instances of the experiment. That's literally impossible to prove, and that's what you're demanding here. You're claiming that just because you can't prove the pricing theory always holds then it's unfalsifiable. That's nonsensical and not how anybody uses the term.

I'm not saying what you think I am saying. The theory that "Uber price is always independent of whether the rider has credits" is indeed falsifiable, and the experiment in the anecdote seems to do so.

The opposite claim, "that Ubers do not always charge the same rate" -- the one that logically flows from falsifying the first -- is the claim that is unfalsifiable.

Is it a valid criticism of the claim? I would generally agree with you and say not really.

How the term is used: https://en.wikipedia.org/wiki/Falsifiability

From Karl Popper: "The only way to verify a claim such as "All swans are white" would be if one could theoretically observe all swans, which is not possible. On the other hand, the falsifiability requirement for an anomalous instance, such as the observation of a single black swan, is theoretically reasonable and sufficient to logically falsify the claim."

How is this different from what I am saying?