We present evidence of crowding out of intrinsic motivation in real purchasing decisions from a field experiment in a large supermarket chain. We compare three instruments, a label, a subsidy, and a neutral price change, in their ability to induce consumers to switch from dirty to clean products. Interestingly, a subsidy framed as an intervention is less effective than either a label or a neutrally framed price change. We argue that this provides a new explanation for crowding behavior: consumers are resistant to having the line of demarcation between public and private decision making moved in either direction.