A plan for estimating the number of "hardcore" drug users in the United States.

This paper describes a program of research that would allow the size, characteristics, and geographic distribution of the "hardcore" population of drug users in the United States to be monitored over time. The program is conceived as a complement to and extension of existing federal data collection initiatives. It involves the development of mathematical models of drug use careers, and the use of these models to estimate the size of the "hardcore" population of drug users within selected geographic areas. These local area estimates are then used in conjunction with more readily available information to estimate the size of the "hardcore" population of drug users in the country as a whole.