Robert Samuelson used his column today to argue against included environmental, equity considerations, or other factors in the measure of the gross domestic product. He is completely right.

Over the decades there have been many efforts to change the measure of GDP to include other factors that we should value under the argument that the output of goods and services is not everything. Of course, the output of goods and services is not everything, but the problem is trying to use GDP as a comprehensive measure of well being. It isn't, and anyone who imagines it is a comprehensive measure of well-being is badly confused.

GDP is a measure of economic output, which is useful to know, but hardly sufficient to tell us whether a country and its people are doing well. A country can have rapid GDP growth, but if it all goes to the richest one percent, it would be hard to see that as a good story. Or if rapid GDP growth went along with extreme environmental degradation, it also would not mean the population was doing well.

The measure of GDP is useful in assessing the health of an economy and society in the same way that weight is a useful measure in assessing a person's health. If a person is five feet and ten inches and weighs 300 pounds, then it is likely they have a problem. On the other hand, they can weigh 160 pounds and still have an inoperable tumor. We would want to know the person's weight to assess their condition, but it will not tell us everything we need to know to evaluate their health.

In the same vein, we identify countries with high per capita GDP, but enormous inequality. It is hard to view these as success stories, since most of the population would not be benefiting from the strength of the economy. However, if a country has a very low per capita GDP or has seen little or no growth over the last two decades, it is unlikely that its population is doing very well. Some countries may consciously choose to have lower GDP for very good reasons. Workers in West Europe put in about 20 percent fewer hours on average than workers in the United States. This allows them to have paid sick days, paid family leave, and 4–6 weeks a year of vacation. Having more family time and leisure are good reasons for sacrificing some amount of output. 

In short, GDP is a useful but limited measure. The problem is not with GDP, but with people who might see it as a comprehensive measure of well-being. It isn't.