tiveness could not be determined because too few collected the necessary follow-
up data. A decade later, the same conclusion holds: Although a few programs may
be promising, none are anywhere near proven. If indicated strategies are to be pur-
sued in the future, we must have more rigorous evaluation designs, including ran-
dom assignment to treatment and, most important, long-term follow-up of both
those in the treatment group and controls. The GAO report did not consider the
efficiency of targeting, but if the goal of prevention is to reduce the net incidence or
prevalence of homelessness rather than merely to provide useful services to poor
people under a politically convenient rubric, targeting is a critical issue. We believe
that indicated strategies (e.g., eviction and foreclosure prevention, supportive ser-
vices for seriously mentally ill people and substance abusers, and discharge plan-
ning) will collectively reach only a minority of people who become homeless.
Even if they were expanded to reach 100% of their intended targets and were also
100% successful in averting the homelessness of those served, they would still pre-
vent fewer than half the annual cases of homelessness. Of course, if an intervention
can prevent even a small number of cases of homelessness in an efficient,
cost-effective manner, it is a worthy undertaking. But we should at least consider
whether broader selected strategies can do better.
durable, biological trait, the former is the often passing, frequently recurring, com-
plex product of shifting structural influences on individual lives. Homelessness is
more the outcome of circumstance--more the product of social contingency--
than the predictable fate of certain sorts of poor people. Given this, it should not
surprise that individual correlates of homelessness, even when bundled, are ineffi-
cient predictors of future homelessness. Indeed, the evidence suggests that it will
never be possible to target services sensitively enough to avoid missing a substan-
tial proportion of people who will become homeless or specifically enough to
avoid serving several people who will not become homeless for every one who
will. To the extent that prevention services are rationed on the basis of individual
characteristics, they inevitably will be burdened with the expensive, invidious, and
scientifically dubious chore of sorting poor people. Further research on targeting
might prove us wrong, but the efficiency of targeting must be demonstrated, not
assumed.
on which scientific targeting relies would need to be periodically renewed in the
areas to which they are applied. This would be costly, though it would keep a small