The idea of the government tallying personal feelings might seem frivolous — or impossibly difficult. For decades, after all, the world has gotten by with gauging a nation’s quality of life on the basis of its GDP, or gross domestic product, the sum of its economic output.

But economists and others have long recognized that GDP, a dollars and cents measure, doesn’t count everything that might be considered important when assessing living conditions.

“Our gross national product, if we should judge America by that, counts air pollution and cigarette advertising, and ambulances to clear our highways of carnage . . .it measures everything, in short, except that which makes life worthwhile,” Robert Kennedy said in a 1968 speech…

According to proponents, a measure of happiness could help assess the success or failure of a range of government policies. It could gauge the virtues of a health benefit or establish whether education has more value than simply higher incomes. It might also detect extremes of inequality or imbalances in how people divide their time between work and leisure.