The Stainless Steel Law appears to be more likely to hold up over a [pg7] large series of cases than the more general Iron Law. This is because the fiercest competition as an explanation for the seeming success of any program—especially human services programs—ordinarily is either self- or administrator-selection of clients. In other words, if one finds that a program appears to be effective, the most likely alternative explanation to judging the program as the cause of that success is that the persons attracted to that program were likely to get better on their own or that the administrators of that program chose those who were already on the road to recovery as clients. As the better research designs—particularly randomized experiments—eliminate that competition, the less likely is a program to show any positive net effect. So the better the research design, the more likely the net impact assessment is likely to be zero.