Schwartz et al. (2014), “Healthier By Precommitment”

Janet Schwartz, Daniel Mochon, Lauren Wyper, Josiase Maroba, Deepak Patel, and Dan Ariely, “Healthier by Precommitment.” Psychological Science 25(2) 538–546, 2014.

• People find it hard to generate the persistent willpower needed to keep actions consistent with intentions. Features such as diffuse, future rewards from resisting temptation might contribute to this difficulty. 

• Financial incentives have been shown to help with weight loss, quitting smoking, and complying with a medical regimen. They might (but only might) even spur the formation of habits, giving temporary financial incentives a lasting impact. 

• Sophisticated folks are aware of their self-control shortfalls, and might welcome commitment devices. 

• The field experiment involved an existing healthy eating program in South Africa that gives 25% cash back at the end of the month for healthy food purchases. Some participants were given the option of forfeiting their cash back if they did not increase their healthy grocery component by five percentage points. The shoppers had no direct positive incentive to take part, they could only lose money relative to not participating (as in this earlier field experiment). A control group was informed about the possibility of such a commitment contract, but was not offered the option to make the commitment. 

• More than one-third of the households offered the commitment contract chose to join the commitment scheme. They were allowed to drop out after one month, however, and about one in six did drop out. 

• The committed shoppers did increase their consumption of healthier items relative to the non-committed shoppers. The commitment seems crucial for converting intentions into future action. But shoppers nonetheless failed to live up to their commitments on average: “…in any given month only one-third of the committed households met their goal.” 

• The standard ethical query applies: Is it ethical to offer (relatively poor?) people a commitment device when it is more than conceivable that many of them will suffer a loss of funds because they will not fulfill their commitment?