  Resource allocation takes place in various kinds of real-world complex
systems, such as the traffic systems, social services institutions or
organizations, or even the ecosystems. The fundamental principle underlying
complex resource-allocation dynamics is Boolean interactions associated with
minority games, as resources are generally limited and agents tend to choose
the least used resource based on available information. A common but harmful
dynamical behavior in resource-allocation systems is herding, where there are
time intervals during which a large majority of the agents compete for a few
resources, leaving many other resources unused. Ac- companying the herd
behavior is thus strong fluctuations with time in the number of resources being
used. In this paper, we articulate and establish that an intuitive control
strategy, namely pinning control, is effective at harnessing the herding
dynamics. In particular, by fixing the choices of resources for a few agents
while leaving majority of the agents free, herding can be eliminated
completely. Our investigation is systematic in that we consider random and
targeted pinning and a variety of network topologies, and we carry out a
comprehensive analysis in the framework of mean-field theory to understand the
working of control. The basic philosophy is then that, when a few agents waive
their freedom to choose resources by receiving sufficient incentives, majority
of the agents benefit in that they will make fair, efficient, and effective use
of the available resources. Our work represents a basic and general framework
to address the fundamental issue of fluctuations in complex dynamical systems
with significant applications to social, economical and political systems.
