Poop, Parks, and Purchasing Power

By: Kevin Lynch

Lately I’ve found myself spending most of my free time in one of two places: parks and grocery stores. While one is a mainstay in my leisure rotation, the other has become part of a new routine, thanks to a recent change in my life: my in-laws. Since arriving from China, they’ve been fascinated by the abundance of open spaces and recreation options here in Reno, but also surprised by how much more expensive it is to eat vegetables in the U.S. than back home. “Cheaper to live on steak,” they often joke.

These conversations have led to weekends spent balancing peaceful walks down sagebrush-lined trails on Peavine with navigating the produce aisles of Trader Joe’s analyzing vegetable prices. And it’s got me thinking: what tells us more about the health of American society: the price of a burger, or the state of our parks?

Both have been held up as defining features of our national identity. When it comes to what matters to voters, Bill Clinton’s political advisor James Carville famously quipped, “It’s the economy, stupid.” On the other hand, historian Wallace Stegner called national parks “the best idea we ever had.” These quotes reflect two values at the heart of the American experiment: individual liberty and the common good. One thrives in the marketplace, the other in open space.

The idea that “it’s cheaper to live on steak” in the U.S. touches on an economic concept called Purchasing Power Parity (PPP). The World Bank describes PPP as measuring “the total amount of goods and services that a single unit of a country's currency can buy in another country.” It helps us understand how far your money goes across borders.

My in-laws expected that prices would be relatively equivalent between the U.S. and China. But they quickly learned that their purchasing power depends on what they’re buying - vegetables, meat, or anything else. If this sounds confusing, don’t worry. It confuses me too. Fortunately, in 1986 The Economist introduced a playful tool to help people grasp PPP: the Big Mac Index.

The Big Mac Index compares the cost of a Big Mac across countries. In 2024, the average price for a Big Mac in the U.S. was $5.69. In China, it was $3.53 - about 38% less. This tells us that the Chinese yuan doesn’t go as far when converted to U.S. dollars, even though it may buy more locally. The Chinese consumer has greater purchasing power within China, but their currency appears weaker when using U.S. prices as a benchmark. In a perfectly efficient global market, a Big Mac would cost the same everywhere. But the disparity tells us something is off, and possibly why: cheap and unsafe labor conditions, environmental shortcuts, protectionist policies, or monopolistic pricing power that distorts true costs to name a few.

If the Big Mac Index is a canary in the free market coal mine, could we imagine a similar rule-of-thumb for gauging things that money can’t buy, like a strong social fabric? Something that doesn’t rely on complex metrics like life expectancy, a Social Capital Index, or surveys of social trust, but instead simply stands in as an indicator of our collective responsibility?

You might think of small voluntary tasks that signal something bigger. Shopping carts returned to their corrals. Hand washing in public restrooms. Drivers’ use of turn signals. Or perhaps - picking up dog waste. Humor me for a moment as I shift from armchair economist to amateur sociologist.

For people to accomplish these seemingly menial tasks, we still need a few things: education to understand the issue, resources to act responsibly, and a sense of community to do our part.  You might call this trio a kind of Social Responsibility Parity: a measure of how evenly civic behavior and care for the commons are distributed across a place; a sort of purchasing power of public participation. And the poop you step in on a morning walk might be a surprisingly good proxy for how we’re doing. Here’s why:

• Education: Not everyone realizes that dog waste is a pollutant, not a fertilizer. Some sincerely believe it’s biodegradable and even beneficial—like the community member who recently asked if it was okay to toss dog waste into their compost. That kind of question reveals something important: the harm is rarely intentional. When people don’t know better, they can’t do better. Awareness is the first step toward collective care.

  
  

• Resources: Last year, 41 volunteers helped us distribute over 663,600 dog waste bags to 97 dispensers across 56 parks, trails, and open spaces. That’s more than 1,800 bags a day, available to help keep waste out of our shared spaces. With tools like these accessible, people are more likely to make the right choice. Sure, dog owners are still responsible even if a station is empty, but access can be the difference between good intentions and good actions. Even the most responsible dog owner can find themselves caught in a downpour with their bags on the other leash. A stocked dispenser can save the day, and the park.

  
  

• Community: Community cohesion can be hard to measure, but it shows up in how people treat shared spaces. In areas with more apartment living and  transient populations, there may be less sense of ownership or long-term accountability. Social norms matter, too. When it’s expected that everyone picks up after their dog, most people do. Even park design plays a role. A Canadian study found that off-leash areas tend to have more dog waste than on-leash ones. Sure, dogs are harder to monitor when running free, but the designation may also imply a looser social contract: more freedom, and perhaps less responsibility.

And that's the gist of Social Responsibility Parity: when people feel part of a place, are aware of the consequences of their actions, and have resources available, they tend to contribute to the common good. And dog waste, or its absence, can help indicate where social responsibility over or underperforms. That brings us to a Big Mac-like tool: the Poop Presence Index, or PPI.

In 2024, volunteers stocked Mira Loma Park with roughly 10,600 dog waste bags. Since dog waste can take up to a year to decompose, that gives us a meaningful timeframe to assess. For simplicity’s sake, let’s assume that all bags used in the park came from us, meaning every properly disposed pile was bagged using one of these.

Ideally, 100% of dog owners would clean up after their pets. But given the real-world factors we’ve discussed, we’ll use a generous Social Responsibility Parity benchmark of 85%. That is, in a community with issue awareness, available resources, and social trust, we might expect 85% of owners to consistently pick up.

Now, let’s look at what we actually found.

On February 22, 2025, we held our inaugural Poop Plot and Pickup Party at Mira Loma. Over two hours, 12 volunteers mapped and removed 205 piles of uncollected dog waste. Of course, not every pile was likely spotted—so let’s conservatively estimate the actual total park poop that day was double that, 410 piles.

Using our bag distribution as a proxy for total owner pickups (10,600 bags used), and estimating total poop incidents (10,600 + 410 = 11,010), we find that dog owners at Mira Loma cleaned up after their pets about 96.27% of the time. That’s well above our 85% benchmark. This PPI suggests that social responsibility at Mira Loma is overperforming.

Now, contrast this with Sierra Vista Park. There, based on our best data, ~1,000 bags were used in 2024 and 600 piles were likely present during our mapping event last month. That puts the cleanup rate at only 62.5%, meaning social responsibility is undervalued or breaking down.

Is this a perfect model? Absolutely not. We’re making a lot of generous assumptions. But even with a large margin of error, this fun exercise highlights something interesting: There seems to be a meaningful difference in social responsibility between these two parks. Using our Social Responsibility Parity framework, we can hazard a few guesses why:

• Education: While general awareness of dog waste harms may be similar across both parks, the type of awareness might differ. At Mira Loma, a manicured community park, people may be more attuned to the impact of waste on lawns and recreation spaces. At Sierra Vista, a large, open-space park, parkgoers may not realize that the same waste is polluting sensitive habitats and waterways. It’s easy to mistake “natural” areas as self-healing, even though they often aren’t.

  
  

• Resources: Dog waste bags are provided at both locations, and the difference in refill rates reflects usage more than access. That said, the design of the parks may influence behavior. Sierra Vista is a 206-acre open space with many informal entry points, while Mira Loma is a more compact, 37.5-acre park with entrances clustered in one area. At Mira Loma, parkgoers are much more likely to encounter a bag dispenser and a trash can during their visit. In contrast, visitors to Sierra Vista might enter far from any station or bin, making proper disposal harder in practice, even if the intent is there.

  
  

• Community: Both parks serve neighborhoods with similar housing patterns, suggesting stable populations and the potential for strong social norms. But norms differ. The City of Reno has a park maintenance facility at Mira Loma, so employees are often present. And even though both parks are technically “leash-required,” it’s common to see off-leash dogs at Sierra Vista due to its open terrain and lower foot traffic. That looser norm may signal a more casual approach to rules in general, including clean-up behavior. 

If the Big Mac Index gives us a greasy glimpse into potential economic imbalances, the Poop Presence Index offers something similar about the state of our shared social life. Dog waste may seem minor, but it quietly registers the presence (or absence) of care, cooperation, and community norms. Poop left behind is not just a nuisance, it’s an indicator. It tells us who feels responsible, who feels seen, and who sees the park as “theirs.” It reflects how well our civic muscles are working: our ability to share space, uphold norms, and protect the commons without being asked or forced. None of this excuses irresponsible behavior. But understanding why people fall short helps us build systems where they’re more likely to succeed.

And hey, if this sounds like the kind of thing you'd like to overthink with us, you're in luck.

Join us at our next Poop Plot and Pickup Party for fieldwork as an amateur dog waste sociologist. Help us map, remove, and reflect on this messy marker of shared social life. It’s volunteer service. It’s community science. And it’s better for you than a Big Mac.

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About the Author:

Kevin Lynch

Kevin is a local to the Truckee Meadows where he received his Master’s of Education from the University of Nevada-Reno with a focus on Career and Technical Education. He enjoys hiking with his wife, geocaching with his daughter, and running or reading all by his lonesome. As a Returned Peace Corps Volunteer and a former AmeriCorps employee, he is excited to continue supporting national and community service with Truckee Meadows Parks Foundation.