Thirty-four polydrug-dependent participants enrolled in a voucher-based substance abuse treatment program were given choices between hypothetical amounts of money and hypothetical amounts of vouchers, which are traded for goods and services, to determine their preferences for the two payment modalities. It was hypothesized that the majority of participants would prefer money to voucher because under the circumstances of the treatment program, the delay associated with money exchange is shorter than the delay associated with voucher exchange. It was further hypothesized that those participants who selected money over voucher also would have greater levels of impulsivity as assessed by the Barratt Impulsiveness Rating Scale (BIS) (Barratt, 1965). The results show large individual differences in money/voucher preference with approximately half of the participants preferring money to voucher when the two amounts are equivalent. In addition, as the magnitude of the money/voucher comparisons increased from $0.50 to $32.00, the percentage of participants that preferred money increased. No correlations were found between money/voucher preference and impulsivity scores. (C) 2000 Elsevier Science Inc.
- Contingency management