During the period 1996 to 2003 the number of GP services per capita in Australia fell by 14 percent and the proportion of services bulk billed (ie provided at no cost to the patient) fell by 12 percentage points. The Government responded to these trends by outlaying hundreds of millions of dollars to increase Government medical insurance rebates, to increase the number of GPs in Australia, and to provide incentives for GPs to bulk bill. ¶ There has been no comprehensive modelling of the GP market to assist in understanding the reasons for either the declining trends or whether the Government responses were successful. This thesis aims to fill that gap. ¶ ...