Ah, I can see what you mean regarding our text, I assume in this passage:
We want to emphasise that this data surprised us and caused us to reevaluate a key assumption we had when we began our impact evaluation. Specifically, we went into this impact evaluation expecting to see some kind of decay per year of giving. In our 2015 impact evaluation, we assumed a decay of 5% (and even this was criticised for seeming optimistic compared to EA Survey data — a criticism we agreed with at the time). Yet, what we in fact seem to be seeing is an increase in average giving per year since taking the Pledge, even when adjusting for inflation.
What you say is right: we agree there seems to be a decay in fulfilment /​ reporting rates (which is what the earlierattrition discussion was mostly about) but we just add the additional observation that giving increasing over time makes up for this.
There is a sense in which we do disagree with that earlier discussion, which is that we think the kind of decay that would be relevant to modelling the value of the Pledge is the decay in average giving over time, and at least here, we do not see a decay. But we could’ve been clearer about this; at least on my reading, I think the paragraph I quoted above conflates different sorts of ‘decay’.
Ah, I can see what you mean regarding our text, I assume in this passage:
What you say is right: we agree there seems to be a decay in fulfilment /​ reporting rates (which is what the earlier attrition discussion was mostly about) but we just add the additional observation that giving increasing over time makes up for this.
There is a sense in which we do disagree with that earlier discussion, which is that we think the kind of decay that would be relevant to modelling the value of the Pledge is the decay in average giving over time, and at least here, we do not see a decay. But we could’ve been clearer about this; at least on my reading, I think the paragraph I quoted above conflates different sorts of ‘decay’.