The study looks at how people volunteer in national parks and why they do it. The researchers found that when the government spends more money on parks, it actually encourages more volunteer work in the parks. They studied data from different parks across the US to see how each park's funding affected the amount of volunteer work done in that park. The results show that for every extra dollar spent by the government on a park, around 27 cents' worth of volunteer time is added in return. This means that public funding can lead to more people volunteering their time to help out in national parks, which is good for everyone involved.