In a past post, riffing on some work done by aacalc.com, I tried to replicate his cost of safety curve where he shows that there are diminishing returns in terms of changes in fail rate for each unit of wealth saved. Then I did it in reverse where, for a given lifestyle (spend rate) changes in wealth (for the worse) will cause fail rates to become way more sensitive at lower wealth levels than high which means it can potentially be an important policy choice. Since the impact is muted for the already retired -- unless one has the ability to change wealth (continue working) or unless one has bad behavioral ticks (panic selling) -- maybe it's not that big of a deal.
Then it dawned on me that for some given inelastic lifestyle, as wealth falls, effective spend rates go up and so there should be a relationship between wealth, effective spend rates, and fail rates. 3D! And who doesn't like 3d? The relationship is probably not all that useful but driving around yesterday I was thinking: "hmm. I wonder what it looks like." This is what it looks like (35k spend rate and some idiosyncratic sim assumptions that match no one, not even me):
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