Kuznets warned of this: “The welfare of a nation can, therefore, scarcely be inferred from a measurement of national income” like the one they created. That hasn’t stopped us from making this misleading number perhaps the most influential statistic in the world.

Americans use G.D.P. in discussions about how well we are doing. It’s at the heart of discussions of whether we are in a recession or not, ahead or falling behind.

Yet, when China “passes” us, it will remain for the most part a very poor country racked with social problems. And as we have seen, though the past decade was marked mostly by United States “growth,” recent Census data shows that since 1999, median American incomes have fallen more than 7 percent while the top 1 percent showed gains. Almost one in four American children live in poverty. We have a high level of unemployment compared to many of our peers.

THE G.D.P. number is not the only culprit, of course. Listening to the news, you might be forgiven if you thought that stock market performance was linked to reality. But markets are oceans of teeming emotions that make the average hormone-infused high school look calmly rational, and much of the “data” that moves markets is just bunk. Trade deficit numbers may be scary but they are also frighteningly flawed, doing a terrible job of accounting for trade in services, trade via the Internet, and inter-company trade, to pick just three among many problem areas.

Worse than the shortcomings of these statistics are the consequences of our over-dependence on them as measures of the success of our society. A country, for example, that overemphasizes G.D.P. growth and market performance is likely to focus policies on the big drivers of those — corporations and financial institutions — even when, as during the recent past, there has been little correlation between the performance of big businesses or elites and that of most people.

Furthermore, of course, the purpose of a society is not merely the creation of wealth, especially if most of it goes to the few. Even John Locke, who famously enumerated our fundamental rights as being to life, liberty and property, qualified this by asserting that people should appropriate only what they could use, leaving “enough and as good” for others. Thomas Jefferson later consciously replaced the right to property with a right to “the pursuit of happiness.” And happiness has become the watchword for those seeking different measures that might better guide governments.

According to the economist Carol Graham, the author of a recent book called “The Pursuit of Happiness: An Economy of Well-Being,” “happiness is, in the end, a much more complicated concept than income. Yet it is also a laudable and much more ambitious policy objective.” While she notes distinctions between approaches to happiness — with some societies more focused on goals like contentment and others on the creation of equal opportunities — she joins a growing chorus of leading thinkers who suggest the time has come to rethink how we measure our performance and how we set our goals.