Status quo bias.

The option already chosen often wins by doing nothing.

A default is what happens when you do nothing. Because changing it takes effort, whoever chooses the default can strongly shape the result.

37% → 86%

Share of workers in a 401(k) plan, before and after enrollment flipped from opt in to automatic.

Madrian & Shea 2001

Look at what happens if you do nothing, because that is the plan you are on. Joining is not the same as saving enough: most people stay at whatever low rate they were handed.

Also under Decision processes.

FramingThe same outcome can feel different when it is described differently.The intention–behavior gapYou can mean to act and still not act when the moment arrives.Salience and attentionWhat is easy to notice can get more weight.Effort and frictionA small immediate cost can change whether an action happens.

Madrian & Shea 2001 · Samuelson & Zeckhauser 1988 · Choi, Laibson, Madrian & Metrick 2002 · Beshears, Choi, Laibson & Madrian 2018