We agree: a rejoinder from Penk and Robinowitz to Sutker and Allain.

We agree with Sutker and Allain (1981) "that voluntarism may prove important in predicting successfulness of drug abuse treatment participation and outcome" (p. 175). Voluntarism also may influence subjective measures of psychopathology by which treatment participation and outcome are assessed. We agree with Sutker and Allain (1981) that factors in addition to voluntarism may affect selfreported psychopathology. We reported ethnic differences 2 years before first commenting on voluntarism (Penk & Robinowitz, 1974). We agree with Sutker and Allain (1981) that degree of self-reported psychopathology may vary, also, as a function of treatment settings. Different types of addicts are likely to be found in different places. Treatment setting as a main effect in the Sutker, Archer, and Allain (1979) study was flawed, however, by a failure to control two confounding factors. One was time of testing; each of their three samples was tested at a different point in time. The second was attrition; two samples, from the Narcotic Addict Rehabilitation Act (NARA) and Fetter Drug Abuse Program, had attrition rates of 5%, the third (Odyssey House, Louisiana), an attrition rate of 50%. Attrition must be controlled because voluntarism also concerns a willingness to remain in treatment. "Controlling" time of testing and attrition in the Sutker et al. manner by allowing them to vary will produce marked treatment setting differences but hopelessly confound the main effect. We agree with Sutker et al., that "there may be a progression of self-report tendencies . . . influenced by voluntarism" (1979, p. 65). NARA volunteers—tested before admission—score higher on the K, D, and Hy. scales of the Minnesota Multiphasic Personality Inventory (MMPI). Fetter samples—tested soon after admission—already are more equivalent in self-reported psychopathology (although we cannot be sure, since