The December effect: How constraints create better leadership decisions

"This isn't holiday spirit. It's design and a great lesson in influence. If leaders learned how to design decisions the way December does, they would get clarity, alignment, and speed all year, and not just when the calendar runs out. The idea is simple. When options shrink, focus increases. When criteria are explicit, choices become easier. When time is clear, commitment accelerates. The research backs this up."

"The question is not why December works. The question is why leaders tolerate the opposite for the other 11 months. What science tells us about too many choices Executives like saying they want "openness." They want to consider every idea, hear every viewpoint, and keep options flexible. In reality, although valuable, this often destroys momentum. The most cited work on this comes from social psychologists Sheena Iyengar and Mark Lepper. Their study showed that people presented with fewer choices were far more likely to act."

"The most cited work on this comes from social psychologists Sheena Iyengar and Mark Lepper. Their study showed that people presented with fewer choices were far more likely to act. A small, curated set of jams led to dramatically higher purchase rates than a large display. That study has been replicated and expanded for two decades. The principle holds in various settings: When options multiply, action collapses."

December creates a tighter decision frame by reducing time, narrowing acceptable options, and clarifying expectations, which accelerates commitment. Leaders often prefer openness and flexibility, but excessive choices and ambiguous criteria undermine momentum. Research by Sheena Iyengar and Mark Lepper shows people act far more when presented with fewer options; curated choices produced dramatically higher purchase rates and the finding has been replicated widely. Simple design moves — limit options, make criteria explicit, and set clear deadlines — increase focus, alignment, and speed. Many organizations tolerate diffuse decision environments for most of the year, losing clarity and traction.

Read at Fast Company