ON THE CRITICAL VALUE FOR PERCOLATION OF MINIMUM-WEIGHT TREES IN THE MEAN-FIELD DISTANCE MODEL David J Aldous Consider the complete $n$-graph with independent exponential (mean $n$) edge-weights. Let $M(c,n)$ be the maximal size of subtree for which the average edge-weight is at most $c$. It is shown that $M(c,n)$ transitions from $o(n)$ to $\Omega(n)$ around some critical value $c(0)$, which can be specified in terms of a fixed point of a mapping on probability distributions.