I think this is related to a general class of mistakes, so I just wrote up a post on it.
This case is a bit different from what that post discusses, in that you’re not focused on a non-critical assumption, but on a non-critical method. We can use VNM rationality for decision-making just fine without computing full utilities for every decision; we just need to compute enough to be confident that we’re making the higher-utility choice. For that purpose we can use tricks like e.g. changing the unit of valuation on the fly, making approximations (as long as we keep track of the error bars), etc.
I think this is related to a general class of mistakes, so I just wrote up a post on it.
This case is a bit different from what that post discusses, in that you’re not focused on a non-critical assumption, but on a non-critical method. We can use VNM rationality for decision-making just fine without computing full utilities for every decision; we just need to compute enough to be confident that we’re making the higher-utility choice. For that purpose we can use tricks like e.g. changing the unit of valuation on the fly, making approximations (as long as we keep track of the error bars), etc.