Operant contingencies and "near-money"

We make two major comments. First, negative reinforcement contingencies may generate some apparent '' drug-like '' aspects of money motivation, and the operant account, properly construed, is both a tool and drug theory. Second, according to Lea & Webley (L&W), one might expect that '' near-money,'' such as frequent-fiver miles, should have a stronger drug and a weaker tool aspect than regular money. Available evidence agrees with this prediction.