The 90% vs 50% Problem
When retirement savings is opt-out, 90% participate. When it's opt-in, 50% do. The same people. The same plan. The only difference is which box was pre-checked.
Behavioral economists Madrian and Shea studied 401(k) enrollment at a large company before and after they switched from opt-in to automatic enrollment.
The results weren't subtle:
Opt-in: 49% participation after one year. Automatic enrollment: 86%.
Same employees. Same plan. Same financial incentive. The only variable was which box came pre-checked.
This is the default effect, and it shows up everywhere HR touches employee behavior. Benefits enrollment. Training sign-ups. Wellness programs. Feedback surveys. Every time you ask employees to take action, your default is doing half the work.
The uncomfortable truth: that opt-in form you spent weeks designing matters less than the checkbox state you set without thinking about it.
The nudge: Audit your top three programs by participation rate. For each one, ask: what happens if someone does nothing? If "nothing" means "not enrolled," you're fighting human inertia instead of using it.
