The properties of a Leontief production technology for Health System Modeling: the Thanzi la Onse model for Malawi

As health system modeling (HSM) advances to include more complete descriptions of the production of healthcare, it is important to establish a robust conceptual characterisation of the production process. For the Thanzi La Onse model in Malawi we have incorporated an approach to production that is based on a form of Leontief technology -- fixed input proportions. At first sight, this form of technology appears restrictive relative to the general conception of a production function employed in economics. In particular, the Leontief technology is associated with constant returns to scale, and level sets that are piecewise linear, both of which are highly restrictive properties. In this article we demonstrate that once incorporated into an all disease, agent-based model these properties are no longer present and the Leontief framework becomes a rich structure for describing healthcare production, and hence for examining the returns to health systems investments.