The monthly jobs report is comprised of two numbers, calculated using two different methods. In May, the economy added an estimated 217,000 jobs and the unemployment rate stayed at 6.3 percent. But looking at those two numbers outside of the context of two other numbers means you're not seeing the full picture.

Jobs numbers and population

Earlier, we noted that the economy hit a post-recession milestone: The number of people employed in the United States has finally passed the level of January 2008, the previous peak. (There are a number of footnotes that could be applied to "number of people employed," but we're going to skip those for now.) Thanks to those 217,000 more jobs, there are about 98,000 more people employed than in that month.

But you can't look at those job gains without looking at another number: population. Below is a graph of the number of people employed in the economy relative to January 2008 ("JOBS") with another set of data, the noninstitutional population of the country relative to the same month ("POPULATION").

That's the shadow. And it shows that job additions since 2010 have essentially kept pace with the growth of the number of people in that same time period.

Unemployment rate and participation

Likewise, you can't just look at the unemployment rate by itself. The unemployment rate is a simple fraction: the number of people employed divided by the number of people in the workforce. If a million people are in the workforce and 800,000 are employed, 80 percent of them are employed and the unemployment rate is 20 percent. Simple enough.

But the size of the workforce fluctuates. People retire, people graduate from college, people go on disability, people just give up on finding work. (The Bureau of Labor Statistics goes into more detail.) So if the workforce suddenly drops to 900,000 in our previous example, eight out of nine people are working, instead of eight out of 10. The unemployment rate goes from 20 percent to 11 percent in a snap, with no one getting a job.

The government counts the percentage of people participating in the workforce, too. And it tracks neatly with the unemployment rate, as you can see in the graph below, which shows the change in percentage rate since January 2008. Participation is the unemployment rate's shadow.

Adding more jobs is unequivocal good news for the country. But the picture that is formed once you include the second set of numbers is very different than what you see with the topline numbers alone.