In the EMS field, the problem of low-acuity, non-emergency individuals who summon an emergency ambulance for simple transport to a local hospital is ever-present. Any person may summon an emergency ambulance and receive transport for the most minor of injury or illness. The consequences of ambulance misuse are many, including emergency resource depletion, increased public cost, and emergency department over-crowding. The Institute of Medicine has outlined these concerns in its most recent report on EMS (IOM, 2006) yet little institutional change has occurred. This dissertation seeks to identify possible incentives and effects of unnecessary emergency ambulance transport. Findings suggest that patient transport to the emergency department via ambulance is influenced by EMS ownership status due to differences in operational funding. Privately owned EMS agencies were found to be much more likely to engage in patient transport than publicly owned agencies. Furthermore, upon arrival to the emergency department, physicians are more likely to provide diagnostic services to ambulance patients. This "ambulance signal" acts through implication that an ambulance patient is more acute simply due to the mode of arrival. The presence of an ambulance signal is evidenced by the inverse relationship between the likelihood of receiving diagnostic services and the ambulance patient’s medical acuity level. Demographic signals (such as age, gender, race, ethnicity, and poverty) are also investigated as enhancers or mediators of the ambulance signal.