Without well designed empirical studies, mathematical models are an important way to use data on needle infection for inferences about human infection. We develop a model with explicit behavioral foundations to explore an array of policy interventions related to HIV transmission among IDU. In our model, needle exchanges affect the spread of HIV in three ways: more HIV-negative IDUs use new needles instead of old ones; needles are retired after fewer uses; and the proportion of HIV-positive IDUs among users of both old and new needles rises owing to sorting effects. The first and second effects reduce the long-run incidence of HIV, while the third effect works in the opposite direction. We compare the results of our model with those of Kaplan and O'Keefe (1993) that is the foundation of man...
The research activities of the NBER are funded by grants from federal research agencies, by private foundations, and by generous donations from our corporate associates and from private individuals. The NBER is a non-profit, 501(c)(3) organization. For information on supporting the NBER, please contact:
Mr. Denis Healy, Director of Development
1050 Massachusetts Avenue
Cambridge, MA 02138-5398