It grabs the headlines, but the number of new jobs created each month barely begins to tell the employment story.

Payroll employment in the United States rose by 115,000 in April. This does not mean that the economy simply added a total of 115,000 jobs; rather, it means that some very large number of new jobs and some very large number of lost jobs resulted in an overall increase of 115,000. Figuring out those two large numbers is much harder and takes much longer than simply noting the net change.

On May 1, the Bureau of Labor Statistics released its most recent count of job gains and losses. With 10 years of data, the picture is clear: In bad times more jobs are lost; in good times more jobs are gained.

2.4 jobs per person

From the beginning of 2001 through the third quarter of 2011, the economy created 316 million jobs and lost 319 million jobs. These are both astonishingly large and astonishingly close numbers.

To put it in perspective, 2.4 jobs were created and 2.4 jobs were lost for every American currently employed. This would suggest tremendous mobility and vitality in the economy. But the details show a more nuanced picture.

In the recession years of 2001 and 2008-09, job losses exceeded job gains by 12.1 million. In contrast, during the three boom years, 2004-06, job gains exceeded job losses by only 6 million. Bad times have been considerably worse than good times have been good.

Looking even closer, we find that both job creation and job destruction have slowed dramatically over the past decade.

By adding the number of jobs created and the number of jobs destroyed each year and plotting it on a graph, we can visualize how volatile employment is over time. I call this job volatility.

From 2001 to 2011, job volatility declined sharply during and immediately after the 2001 recession. It evened out during the mid-decade boom, but dropped again in the Great Recession. It is leveling off in the present recovery but at a much lower level.

I suspect this trend is related to and reflects the decline in the labor participation rate.

Blighted from birth

The percent of Americans over age 16 in the labor force has dropped drastically from nearly 67 percent to 63.5 percent over the last 10 years.

Of course, every person who stops looking for a job has his or her own reasons, but individual circumstances should not blind us to a central fact: Fewer Americans need to work to provide all the goods and services consumers need. Indeed, fewer Americans have to work to keep the U.S. economy the strongest in the world.

Economists have a typically cold-blooded term for describing this phenomenon: the Non-Accelerating Inflation Rate of Unemployment, or NAIRU (pronounced like the former Indian prime minister).

It means that in order for the economy to adjust dynamically to changing demands, technologies and competition, some fairly significant percentage of would-be employees will always be out of work. Employees are the economys unwilling elastic.

In one sense NAIRU is an obvious concept. Its alternative is a command economy in which people have jobs for life, few businesses are created and fewer still are allowed to die.

Its an approach that has been tried and found wanting. As factory hands in the old Soviet Union used to say, We pretend to work and they pretend to pay us.

The problem, though, is that nobody knows what the lowest sustainable rate of unemployment actually is. Economists tend to come to the ex post facto conclusion that NAIRU is simply the current unemployment rate.

In the boom periods of the 1990s, they said that the NAIRU might be as low as 4 to 5 percent; now they are saying it may be 7 to 8 percent. But this is more than an academic exercise.

If an ever-smaller proportion of the population is necessary to keep the economy running, how will the growing number of non-workers live? In my opinion, this will be the great social and political question of the next 50 years.

If addressed constructively, it will result in a redefinition of usefulness and productivity. If ignored, it will perpetuate an underclass whose hopes for a better life will be blighted from birth.

David Oser is a senior vice president and CFO of Craft3. The views expressed are his and not necessarily those of Craft3. Craft3 is a nonprofit community development financial institution with a mission to strengthen economic, ecological and family resilience in Pacific Northwest communities.