The natural response to all this is to ask whether happiness research is really reliable enough to be used by policymakers. Researchers have paid close attention to this issue, and, after much testing, have found that the answers people give to questions about their well-being seem to correspond fairly well to more objective evidence.

People who claim to be happy tend to live longer, commit suicide and abuse drugs and alcohol less often, get promoted more frequently by their employers, and enjoy more good friends and lasting marriages. Their assessments of their own well-being also align quite closely with the opinions of friends and family members.

So, overall, statistics about happiness seem to be as accurate as many of the statistics regularly used by politicians, such as public-opinion polls, poverty rates, or, for that matter, GDP growth - all of which are riddled with imperfections.

Of course, happiness research is still new. Many questions remain unexplored, some studies lack sufficient confirmatory evidence, and still others, like those involving the effects of economic growth, have yielded conflicting results.

Thus, it would be premature to base bold new policies on happiness research alone, or to follow the example of tiny Bhutan by adopting gross national happiness as a nation's principal goal. Yet the findings may be useful to lawmakers even today - for example, in assigning priorities among several plausible initiatives, or in identifying new possibilities for policy interventions that deserve further study.

At the very least, governments should follow Great Britain and France and consider publishing regular statistics on trends in the well-being of their citizens. Such findings will surely stimulate useful public discussion while yielding valuable data for investigators to use.

Beyond that, who knows? Further research will doubtless provide more detailed and reliable information about the kinds of policies that add to people's happiness. Someday, perhaps, public officials may even use the research to inform their decisions. After all, what could matter more to their constituents than happiness?

The author was president of Harvard University from 1971 to 1991 and again from 2006 to 2007.

Project Syndicate.