  We present a generalized dynamical model describing the sharing of
information, and corresponding herd behavior, in a population based on the
recent model proposed by Eguiluz and Zimmermann. By introducing a
size-dependent probability for dissociation of a cluster, we show that the
exponent characterizing the distribution of cluster sizes becomes
model-dependent and non-universal. The resulting system, which provides a
simplified model of a financial market, yields power law behavior with an
easily tunable exponent.
