Table 3.
Number of Abstinent Days During the Voucher Period in Each Condition as Predicted by Baseline Demand Indices
| Voucher period | ||||
|---|---|---|---|---|
| β | sr 2 | F (1, 164) | P | |
| Noncontingent vouchers condition | ||||
| Intensity | −0.15 | 0.02 | 3.80 | .05 |
| Breakpoint | −0.15 | 0.02 | 3.67 | .06 |
| Omax | −0.15 | 0.02 | 3.90 | .05 |
| Elasticity | 0.19 | 0.04 | 5.99 | .02 |
| Contingent vouchers condition | ||||
| Intensity | −0.04 | <0.001 | 0.21 | .65 |
| Breakpoint | −0.007 | <0.001 | 0.009 | .93 |
| Omax | −0.03 | <0.001 | 0.17 | .68 |
| Elasticity | 0.02 | <0.001 | 0.09 | .77 |
Abstinent days based on two carbon monoxide readings indicative of abstinence; sr2 indicates percentage of variance accounted for by the predictor.