UX experiments / Choice design
Choice design · Natural experiment · policy change
Opt in or enrolled by default: what happened to retirement savings?
Retirement savings plan: employees opt in, or are enrolled automatically and can opt out?
Make your call. Which version won, and why? Decide before you open the result. Guessing first is what trains your judgment.
Made your call? See the result
Participation rose from 37% to 86%.
What happened
New hires under automatic enrollment joined at far higher rates, though many stayed at the default contribution rate.
Why it worked
Most people keep the default. The default is a decision the designer makes for everyone who doesn't decide.
The takeaway
Choose defaults deliberately, and check what people get stuck at.
Source
More experiments to call
Practice the call
Call experiments like these every day.
Irreplaceable gives you a few real experiments a day to call before you see the result, and tracks how your judgment improves. Start with a free baseline: 12 decisions, about 12 minutes.