The Goal-Gradient Effect
Coffee buyers sped up with every stamp on a loyalty card, then slowed right back down once they started a fresh one. Effort follows distance to the finish line.
The Goal-Gradient Effect is the tendency to speed up as a goal gets close. Clark Hull saw it in rats in 1934: they ran faster the nearer they got to food.
In 2006 Ran Kivetz, Oleg Urminsky and Yuhuang Zheng found the same curve in a campus café at Columbia University. Members of a buy-10-get-one-free coffee program bought more often with every stamp. The gap between purchases shrank about 20 percent from the first stamp to the last, so cards filled nearly five days sooner than the opening pace predicted.
The useful part came next. Once customers earned the free coffee and started a new card, they slowed right back down to their opening pace. The researchers called it postreward resetting. Effort tracked distance to the goal, and each new card reset the distance.
The Endowed Progress Effect is about a head start at the beginning. This one describes the whole shape of effort: slow at the start, fast near the end, slow again after.
The nudge: A six-month project has one finish line and a long, flat middle. Cut it into two-week milestones the team can see, so everyone is always close to one. Same work, more finish lines.
Source: Kivetz, Urminsky & Zheng, The Goal-Gradient Hypothesis Resurrected: Purchase Acceleration, Illusionary Goal Progress, and Customer Retention, Journal of Marketing Research (2006)
