Duke and Duchess Visit Bhutan, Famous for National Happiness Index

The Duke and Duchess of Cambridge are visiting Bhutan, which has a GNP, not GDP.

"It is a very small, homogeneous and very traditional country," Graham said. Bhutan's population is about 750,000.

Among the nearly 150 questions in the 2015 survey were, "How did air pollution affect your life?" and "Do you consider Karma in the course of your daily life?" The survey questionnaires for 2015, 2010 and 2008 are posted to the official GrossNationalHappiness.com website.

Bhutan has been relatively successful at mitigating poverty, increasing literacy and health, preserving their culture, environment and psychological well-being, Graham said. The country's largest export is hydropower to India.

"They are also starting to have some real modernization challenges, like trying to control the internet, which does not work, and a next generation that does not want to be bound by the same norms," she said.

There are a couple reasons why a national index on happiness could be problematic in the U.S., Graham said.

First, the size and diversity of U.S. residents would make it difficult to accurately and regularly measure factors like health, Graham said.

"A large number of surveys fall under government statistics here," Graham said, adding that the National Institutes of Health and the Department of Labor try to capture various factors of what could be considered well-being.

Second, Graham said the data would be immediately politicized, she said.

"Once you say 'gross national happiness,' it could be easily manipulated by politicians," she said. "I think it would kill the idea of well being in this country."

Though it could be helpful for some policy makers to have one simple index, Graham said it won't necessarily make everyone happier. And there could be some findings that many people may already know, such as that people who exercise may be happier.

"It's not rocket science," Graham said.

Canada and Britain are two of the countries smaller than the U.S. that try to measure residents' well-being to inform policy decisions.

While the Census Bureau collects data every 10 years, Graham said a survey that measures well-being would be most useful at least annually. But that would be difficult to do in the U.S. In Santa Monica, California, the well-being of the city's 90,000 residents was measured in a two-year effort.

Then there's the question of what came first: the happiness or the index? It could be possible that people in Bhutan are happier because the country has made "happiness" one of the nation's priorities.

"I would say they would score higher than Nepal or India, but they're not unusually happy," Graham said. "They're still a developing country with a lot of challenges."