Organ Donors and Lost Wallets: The Surprising Ways Economists Measure Trust
Organ Donors and Lost Wallets: The Surprising Ways Economists Measure Trust
March 17, 2025
March 17, 2025
Imagine walking into a small boutique shop in Moscow and being greeted not just by a salesperson, but by a security guard—something that happens in virtually every Russian store, regardless of size. Now picture a street vendor in Oslo leaving their merchandise unattended with just an honor box for payments while they take a bathroom break. What explains this stark difference? One word: trust.
In discussion section today, we were diving into German reunification, and several students expressed outright contempt when we got to the part where the assigned reading used organ donor sign-up rates as a measure of trust. But as we unpacked it, I realized this methodological choice reveals something fascinating about how economists attempt to measure seemingly intangible social factors—and why these measurements matter enormously for understanding economic outcomes.
If you've taken an intro econ course, you might think economists only care about things we can count, like GDP or unemployment rates. But increasingly, economists recognize that "softer" social factors like trust have enormous economic consequences. The question is: how do you measure something as subjective as trust?
The most straightforward approach is simply asking people if they trust others. The World Values Survey famously asks: "Generally speaking, would you say that most people can be trusted?" This produces some striking variations across countries—over 60% of Swedes and Norwegians say most people can be trusted, compared to under 10% in Brazil (Our World in Data, 2022).
This approach is clean, simple, and lets us compare across countries and time. But there's an obvious problem: what people say about trust might not match how they actually behave when trust is on the line. Researchers have found only weak correlations between survey responses and actual trusting behavior (Glaeser et al., 2000).
This is where behavioral economists step in with clever experiments. The classic "trust game" introduced by Berg, Dickhaut, and McCabe (1995) works like this:
Player 1 gets some money and can send any amount to Player 2
Whatever amount is sent gets tripled
Player 2 can then return any amount back to Player 1
The amount Player 1 sends measures trust, while what Player 2 returns indicates trustworthiness. Pretty elegant, right?
Here's the kicker: research shows only a weak correlation between what people say about trust in surveys and how they act in trust games (Fehr et al., 2003; Glaeser et al., 2000). Someone might claim they trust others but then send very little in the experiment, or vice versa.
Some researchers have gotten even more creative. In 2019, scientists "lost" over 17,000 wallets across 40 countries to see if people would return them (Cohn et al., 2019). Surprisingly, in 38 out of 40 countries, wallets with more money were more likely to be returned. Return rates ranged from 14% in China to 76% in Switzerland. This clever field experiment provides a real-world measure of civic honesty and trustworthiness that avoids the artificiality of laboratory settings.
But the measure I find most fascinating—the one that sparked this whole blog post—is using organ donor registration rates as an indicator of trust. Unlike the trust game, which measures interpersonal trust, donor registries tell us something about institutional trust: Do people trust the medical system and broader institutions to handle their organs ethically?
The international comparisons are revealing:
Spain has the world's highest organ donation rate (about 36 deceased donors per million people). They use an "opt-out" system, but officials emphasize that the success comes from a well-organized transplant system that has earned public trust. If donation rates start dropping, Spanish authorities view it as a sign that their system's trustworthiness is failing.
Germany provides a cautionary tale. After a 2013 scandal where doctors manipulated patient data to game the organ allocation system, public confidence collapsed. Years later, Germany's donor rate remains very low (around 10 per million). The key lesson? Transparency and fairness are crucial—when trust breaks, it's exceedingly difficult to rebuild.
Brazil's experience is even more dramatic. In 1998, they implemented an "opt-out" system to boost donations. But without sufficient public education or infrastructure, the policy triggered widespread panic. Many citizens feared abuse in a system with uneven healthcare access. The backlash was so severe that Brazil repealed the law within a year and returned to an opt-in system.
These cases illustrate why organ donor registries function as implicit trust barometers. High registration rates reflect confidence in medical institutions and the belief that one's altruism won't be exploited. Conversely, scandals or poorly communicated policies can rapidly erode trust and tank donor numbers.
For economists studying institutional development, these patterns provide a valuable proxy measure—one that captures actual behavioral choices rather than just stated opinions.
This isn't just academic curiosity. Trust correlates strongly with economic prosperity—countries with higher trust levels generally have higher GDP per capita. And the causal mechanism makes intuitive sense.
As Nobel-winning economist Kenneth Arrow noted, "virtually every commercial transaction has within itself an element of trust." When trust is high, transaction costs plummet. You don't need expensive legal safeguards, monitoring systems, or enforcement mechanisms if you trust your counterparty will honor their commitments.
The numbers are striking: one analysis found that a 10 percentage-point increase in the share of trusting people in a country tends to raise annual per capita GDP growth by about 0.5 percentage points (Deloitte, 2016). Over decades, this compound effect becomes enormous. Knack and Keefer (1997) similarly found that an increase of one standard deviation in trust is associated with more than half a standard deviation higher economic growth rate.
At the micro level, trust affects everything from entrepreneurship to innovation. In high-trust environments, firms collaborate more easily, investors take more risks, and markets function more efficiently.
What I find most compelling about the research on trust is how something so "soft" and sociological turns out to have such "hard" economic consequences. Trust functions as a kind of invisible infrastructure that enables economic exchange and cooperation at scale.
So the next time you hear economists debating growth policies focused solely on interest rates, taxes, or regulations, remember that the invisible foundation of trust might be just as important—even if measuring it requires dropping wallets, playing lab games, or examining organ donor registries.
And for my fellow economics students: paying attention to these creative measurement techniques can open up entirely new research avenues. Sometimes the most revealing economic indicators aren't found in standard datasets, but in the everyday choices that reveal whether people trust each other—and the institutions that govern their lives.
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