This article analyses the processes of market-driven change in two pro
fessional service sectors, Research and Development (R&D) and the Nati
onal Health Service. Building on these sectors' common experiences, th
e article proposes a general model of market-driven change in professi
onal services, highlighting the complex and multi-level nature of the
process. It is argued that, while market-driven change is an increasin
gly practised and observed phenomenon, its complexity has been widely
underestimated. For managers, the problem is one of synchrony between
different levels in the change process, with the top strategic level p
articularly liable to lag changes at other levels. For academic observ
ers of new market forms of control, the risk is of repeating the simpl
ifications of early 'labour process' analyses of hierarchical control.