The U.S. health care industry has been hampered in the development of a mature marketing function in part due to characteristics unique to the industry. These characteristics include a lack of market data, poorly developed market research techniques, and a poor understanding of consumer behavior within the industry. Some of the deficiencies are being addressed through the development of an emerging field that is being referred to as "health demography." Health demography and those who have begun to refer to themselves as health demographers are drawing from the fields of demography, epidemiology, biostatistics, and the social sciences to formulate a new discipline uniquely related to the needs of today's health care marketers and planners. Those involved with health demography are developing databases and models for application to concrete problems in health care delivery. The development of this field is contributing to the advancement of the state of marketing in health care and serving to reduce many of the barriers that have retarded the development of a mature marketing function within the health care industry.