AMERICA'S NATIONAL PARKS encompass some of the country’s most iconic sights, from the Statue of Liberty to the Rocky Mountains to the giant sequoias of Yosemite. For people around the world, these and other wonders—the Grand Canyon, Yellowstone—are indelible symbols of a vast, unspoiled legacy encompassing 84 million acres. As the National Park Service (NPS) celebrates a relatively youthful centennial this year, there's an unspoken sense that the parks have always been around and always will be—after all, part of the NPS’s mission is stewardship for the enjoyment of future generations.

But how much are the parks really worth to us? If it came down to it, how much would we be willing to pay to preserve them in their current state? Daniel Patrick Moynihan Senior Lecturer Linda J. Bilmes at the Harvard Kennedy School and a small army of Kennedy School students have made it their business to answer those questions by taking on the seemingly impossible task of measuring how much the U.S. public actually values the existence of national park lands and programs (such as education, scientific research, historical stewardship, wildlife protection)—regardless of whether they have visited the parks or not. Their calculation: $92 billion.

Revenues generated by park visitation fees and tourism spending have been the typical metric to date for measuring economic impact. What is different, and unprecedented, about the work being done by Bilmes and her students is its multifaceted approach to putting a big-picture price tag on an entity that many American citizens consider a birthright.

“It’s difficult to hang a value on the priceless things, but it’s even worse not to try,” says Bilmes, who in the past has written about cost, not value, in The Three Trillion Dollar War: The True Cost of the Iraq Conflict. “Thinking of the value of the parks only in terms of the people who visit them isn’t sufficient because they’re part of a legacy that Americans want to protect and pass on to their descendants.”

Bilmes reached this conclusion as a result of a "willingness-to-pay" survey of the general public she conducted in two rounds with John Loomis and Michelle Haefele of Colorado State University. Both samples, collected from the end of 2013 to mid-2015, showed that 95 percent of respondents felt it was important to protect historic sites for current and future use whether they visited them or not. In other findings, just over 22 percent indicated that private business could probably do a better job of protecting sites than the federal government.

The authors estimated the Total Economic Value (TEV) by administering a survey in which participants were asked how much they would be willing to pay in additional taxes to not lose 20 percent of the parks and park programs. The survey instrument was developed in a series of focus groups, which showed that the public felt it was realistic to imagine a 20 percent cut to the NPS due to the national budget situation. By varying the amounts of money respondents could pay in the survey for various levels of land protection, the authors developed a model of the public's willingness-to-pay.

The result is a TEV of $92 billion for the NPS. This represents the total amount the U.S. public says it would be willing to pay in annual taxes so as not to lose national parks and programs. Put in other terms, 80 percent of respondents were willing to pay higher taxes to not be deprived of the parks.

The study found significant value in national parks ($60 billion) but also in the programs of the NPS—programs to protect historic buildings, natural landmarks, and educational programs within and outside national parks, valued at $32 billion. Previous research, which had focused only on visitor spending, had estimated a total value of $31 billion in economic output from $16.9 billion in visitor spending.

The yearly federal appropriation to the NPS is less than $3 billion—and it has been declining in real terms since 2001, Bilmes notes.

(The study was conducted independently of the NPS. Bilmes serves on the advisory board of the National Park System, a 12-person congressionally chartered panel that advises the secretary of interior and the director of the NPS on the designation of national historic landmarks and national natural landmarks, and other matters related to the National Park System.)

The TEV study is part of a larger effort that Bilmes has led to document a wide range of non-visitation benefits of the national parks—including carbon sequestration and watershed protection, the NPS role in education, and creation of intellectual property (such as filming of movies). The many categories of value were identified by Francis Choi and Tim Marlowe (both MPP 2012) in their Policy Analysis Exercise “The Value of America’s Greatest Idea,” which won the Christopher P. Kaneb Prize for the Best Masters Student Paper awarded by The Harvard Environmental Economics Program.

separate paper, co-authored by Bilmes, Loomis, and Adam Banasiak MPP 2014, finds that carbon sequestration on NPS land (excluding Alaska) amounts to 17.5 million metric tons of CO2, valued at $707 million annually. The authors plan to release several additional papers this year, including one that estimates the value-added of intellectual property. The authors have identified more than 800 major films and TV shows that were produced on NPS lands—many of which became blockbusters. For example, George Lucas paid almost nothing to film the Star Wars series in Death Valley (it would go on to gross $4 billion). “Some of the most iconic movie scenes of all time have been filmed on NPS properties,” says Bilmes, “including Badlands National Park (Dances with Wolves), Mt. Rushmore (North by Northwest), and Arches National Park (Thelma and Louise).”

Findings on other aspects of valuation, including watershed protection, will continue to roll out during the national parks’ centennial year, with a book to come in 2017. It seems a suitably sweeping, large-scale treatment for an equally vast resource. “All of these places are irreplaceable in different ways,” says Bilmes. “At Gettysburg, you can stand in front of a tree that still has a cannonball embedded in it from the Civil War. In essence, the national parks are the American story.” Grasping the value of that story could help ensure its existence for generations to come.

Get smart & reliable public policy insights right in your inbox.