In the context of serious concerns over the affordability of healthcare, various authors and international
policy bodies advise that strategic purchasing is a key means of improving health system performance. Such advice is
typically informed by theories from the economics of organization (EOO). This paper proposes that these theories are insufficient for a full understanding of strategic purchasing in healthcare, because they focus on safeguarding against poor performance and ignore the coordination and adaptation needed to improve performance. We suggest that insights from other, complementary theories are needed.