  Simulational studies of spin glasses in the last decade have focussed on the
so-called replicon exponent $\alpha$ as a means of determining whether the
low-temperature phase of spin glasses is described by the replica symmetry
breaking picture of Parisi or by the droplet-scaling picture. On the latter
picture, it should be zero, but we shall argue that it will only be zero for
systems of linear dimension $L > L^*$. The crossover length $L^*$ may be of the
order of hundreds of lattice spacings in three dimensions and approach infinity
in 6 dimensions. We use the droplet-scaling picture to show that the apparent
non-zero value of $\alpha$ when $L < L^*$ should be $2 \theta$, where $\theta$
is the domain wall energy scaling exponent, This formula is in reasonable
agreement with the reported values of $\alpha$.
