The critical number of slots needed in San Francisco to maintain a queue length of zero varied substantially under our four scenarios. Specifically, if tolerance for delay averages one year, the number of slots needed is only 6715 appreciably less than expected. Moreover, queue reductions would not occur instantaneously. Our results indicate that increasing slots to the necessary minimum would require ten to fifteen years to achieve substantial reductions, although this timeframe can be reduced by greater initial increases in capacity. The current situation in San Francisco is consistent with these estimates.
Treatment has direct and indirect benefits.
Indirect benefits are ultimately larger, but accrue over time. The capacity needed to achieve treatment on demand is likely greater than usually supposed, and the timeframe for implementation of the program longer. Our analysis indicates that it need not, although it may take considerable time to achieve the policy s full benefits. The benefits of augmenting treatment capacity are realized as increasing numbers of persons are removed from drug use. Rates for activities such as crime, unemployment, and child abuse, as well as the incidence of infectious diseases such as HIV, differ for those who use drugs and those who do not.