The Hofstadter Law

I learnt about this very truthful and funny law, the Hofstadter's Law (HL): 

It always takes longer than you expect, even when you take into account Hofstadter's Law. (From Godel, Escher, Bach, p. x)

I see this law as an ingenious recursive corollary of Murphy's Law which actually has been, at least implicitly, at work in construction planning, and project management forever (yes, perhaps since the Babel Tower, and the Pyramids). To come up with a higher order law that actually incorporates the prediction of this law into a higher order predictive time scheme, would be according to the HL, another HL.