Interesting! Proportional pledges kind of violates the bright line principle. It’s not totally crazy or anything but my gut feeling is that we shouldn’t do this. I think we’d keep it separate from this pledge schedule redesign in any case.
True, and good point, though it’s just one day so maybe that’s fine? Also I’m not sure proportional pledges are well-defined in the case of weight loss. There’s no bound to how much you could exceed your hard cap by, so how would Beeminder compute the fraction of your pledge to charge you? I suppose we could just pick something, like exceeding it by your daily rate or your specified max fluctuation is a 100% derailment and anything less is pro-rated. (But again, we’ll probably set this aside from the current pledge schedule redesign. I love how you’re thinking, btw. It’s possible this idea will end up growing on me!)
Proportional pledges might already be too much complexity and I’m pretty sure that this would be! (Still love how you think though!) Actually I may even have a philosophical objection to this one. It fuzzifies the consequences of derailing and I claim that that always backfires. See blog.beeminder.com/catchup and Beeminder’s No Free Lunch Theorem. That might apply to proportional pledges too. I’m still thinking about that; but I guess we shouldn’t get too side-tracked by these more academic questions, fun as they are!