Pay‐for‐performance (P4P) is a widely implemented quality improvement strategy in health care that has generated much enthusiasm, but only limited empirical evidence to support its effectiveness. Researchers have speculated that flawed program designs or weak financial incentives may be to blame, but the reason for P4P's limited success may be more fundamental. When P4P rewards multiple services, it creates a special case of the well‐known multitasking problem, where incentives to increase some rewarded activities are blunted by countervailing incentives to focus on other rewarded activities: these incentives may cancel each other out with little net effect on quality. This paper analyzes the comparative statics of a P4P model to show that when P4P rewards multiple services in a setting of multitasking and joint production, the change in both rewarded and unrewarded services is generally ambiguous. This result contrasts with the commonly held intuition that P4P should increase rewarded activities. Copyright © 2015 John Wiley & Sons, Ltd.