Several, apparently distinct, formalisms exist in the literature for
predicting the clustering of dark matter halos. It has been noticed on a
case-by-case basis that the predictions of these different methods agree in
specific examples, but there is no general proof that they are equivalent. In
this paper, we give a simple proof of the mathematical equivalence of barrier
crossing, peak-background split, and local biasing.Comment: 20 pages, 1 figur