The Science of Generosity
Rigorous peer-reviewed research confirms what Karma Kitchen experiences every week: when you frame a transaction as a gift for someone else, people become remarkably more generous.
People pay significantly more under "pay-it-forward" pricing than "pay-what-you-want" — even though both are financially identical to the business.
Field Experiment Results
Four studies across different settings consistently showed that pay-it-forward increases generosity
| Study | Pay-What-You-Want | Pay-It-Forward | Increase |
|---|---|---|---|
|
Study 1
Cartoon Art Museum, SF
|
$1.89 | $2.67 | +41% |
|
Study 2
Cartoon Art Museum, SF (replication)
|
$2.19 | $3.07 | +40% |
|
Study 3
Cartoon Art Museum + Gift Shop
|
$2.64 | $3.58 | +36% |
|
Study 4
Gourmet Coffee Vendor, Oakland
|
$1.93 | $2.33 | +21% |
The Power of "Giving" Over "Receiving"
In a follow-up experiment conducted at Karma Kitchen itself, researchers tested whether it matters how you frame the pay-it-forward message.
Some guests received cards emphasizing they had received a gift: "Someone who came earlier paid for your meal." Others received cards emphasizing they could give a gift: "You have a chance to pay for someone who will come later."
The results were striking. Simply shifting the frame from receiving to giving nearly doubled what people chose to pay. This suggests that generosity isn't primarily driven by obligation or reciprocity — it's driven by the opportunity to be generous.
Why Does This Work?
The research identified several psychological mechanisms behind increased generosity
Social Norm Perception
People overestimate what others pay under pay-it-forward, then match that perceived norm. They want to be as generous as they believe others are being.
Identity Reinforcement
Giving to others enhances one's identity as a capable, caring person. The act of giving strengthens how we see ourselves, which feels intrinsically rewarding.
Indirect Reciprocity
Unlike direct exchanges with sellers, pay-it-forward creates a symbolic social relationship with other customers — a chain of kindness that feels meaningful to continue.
The authors want to thank ServiceSpace community for their persistent and kind support.
— From the published paper's acknowledgmentsKarma Kitchen: A Living Laboratory
Karma Kitchen wasn't just studied by these researchers — it was a direct partner in the research. The "giving vs. receiving" experiment was conducted at our Berkeley location, with real guests making real payment decisions.
Since 2007, Karma Kitchen has served as a living laboratory for gift economy principles, demonstrating week after week that when you trust people with generosity, they rise to the occasion.
Read the Research
Access the original peer-reviewed papers
Pay What You Want vs. Pay It Forward: Field and Lab Experiments
Research presentation summarizing key findings from field experiments at museums, coffee vendors, and Karma Kitchen.
Paying More When Paying for Others
Full peer-reviewed paper published in the Journal of Personality and Social Psychology (2014).
What This Means
Implications for gift economy and beyond
Generosity Is Natural
People aren't purely self-interested. Given the right context, they consistently choose to be generous — even when they could pay nothing.
Framing Matters
How you present an opportunity dramatically affects behavior. Emphasizing giving over receiving nearly doubled contributions.Trust Creates Value
Pay-it-forward pricing generates more revenue than pay-what-you-want — proving that trust-based models can be economically sustainable.
Replicable Model
These effects held across museums, coffee shops, and restaurants — suggesting the principles apply broadly, not just in special contexts.
See the Research in Action
Every week at Karma Kitchen locations around the world, these principles come to life. Experience it yourself or bring this model to your community.