Reserved-For-You Messaging
Tell people something has been set aside just for them and the endowment effect makes them want it.
- Difficulty
- Starter
- Time to result
- ~days to results
- Steps
- 4
- Confidence
- 90%
In a message tournament with ~150 scientists testing dozens of vaccine-reminder messages on hundreds of thousands of Americans, the winner told recipients a vaccine had been 'reserved for you' or was 'waiting for you.' The framing works via the endowment effect — we value what already feels like ours and don't want to lose it — while also implying a provider recommendation and a hint of scarcity. It proved robust whether people had to travel to a pharmacy or were offered a shot at an existing appointment. Later UCLA research showed the same 'reserved for you' language lifts conference registrations and book downloads too.
Origin
The finding came out of the Behavior Change for Good initiative's megastudy on COVID and flu vaccine reminders, co-directed by Milkman and Angela Duckworth, where 'reserved for you' beat humor and social-norm messages.
Core principles
- 01We value things that already belong to us more than things that merely could belong to us (the endowment effect).
- 02'Reserved for you' framing implies a recommendation, ownership, and possible scarcity all at once.
- 03The effect is robust across contexts, from vaccines to conference sign-ups to book downloads.
How to run it
- 1
Start with a reminder
Send a simple reminder to act — even bare reminders significantly lift follow-through.
Pro tip Repeat reminders; repeated nudges outperform single ones and we under-nag.
- 2
Add the reserved framing
Tell the recipient the thing has been reserved for them or is waiting for them.
Pro tip Phrases like 'your X is reserved for you' trigger the endowment effect.
- 3
Let it imply recommendation and scarcity
The framing signals a provider recommendation and that not everyone has one set aside, adding desirability.
- 4
Keep it honest
Only use the tactic for actions genuinely in the person's interest, not manipulation.
Watch out A nudge should push toward a choice the person would already favor with full information.
In the wild
Milkman's team tested dozens of vaccine-reminder messages — humor, social norms, and more — across hundreds of thousands of people.
→ The 'a vaccine is reserved for you / waiting for you' message rose to the top and was robust across settings.
A UCLA team applied the same reserved-for-you language to conference registrations and audiobook or e-book downloads.
→ People were more likely to register and download when the item was framed as reserved for them.
Common mistakes
Relying on a single reminder
One reminder underperforms repeated ones; people under-nag and lose follow-through they could have captured.
Using it to manipulate
A nudge should steer people toward a choice they'd already favor with full information, not toward something against their interest.
Is it for you?
Best for
Nudging follow-through on actions people already intend to take — sign-ups, appointments, downloads.
Not ideal for
Persuading the genuinely hesitant, or pushing actions not in the recipient's interest.
From the transcript
“the best performer said a vaccine is reserved for you or it's waiting for you so that it feels like it already belongs to you”
“we value things that belong to us more than things that could belong to us or belong to other people it's called the endowment effect”
From the episode
Katy Milkman: The Science of Change
Katy Milkman