Suppose in May you spent $47 more than you took home and in June spent $51 more than you took home. It would seem May was a slightly better month. 

Now let’s suppose in May you spent $2,047 against take-home pay of $2,000, but in June you took home $10,000 and spent $10,051. Despite the difference in the bottom line, you probably had a much better June than May.

That’s what Tuesday’s report from the Bureau of Labor Statistics -- the monthly Job Openings and Labor Turnover Survey or “JOLTS” -- will tell us. It won't show us where we wound up (indeed, the economy did lose 51,000 jobs in June and 47,000 in May), but how we got there – namely, the number of hirings and job separations in the month. And, complementing the unemployment rate, which measures excess supply in the labor force, Tuesday’s report details job openings, measuring excess demand for workers. In that way we can match the supply of jobs (openings) against the demand (unemployment) or the other way: the supply labor (unemployment) against demand (job openings).

If you haven’t heard very much about JOLTS, you’re not alone. It is nowhere near the “top 10” of economic releases reported by the business press or economists.

“It doesn't get more play mostly due to inertia,” offered Dean Baker of the Center for Economic Policy Research. “A lot of economists are not very familiar with it. We always feel better talking about series that we have used for a long period.”

Even without knowing the specific numbers to be reported Tuesday, we can read something from the trends. According to JOLTS, hiring peaked in July, using a smoothing three-month moving average that adjusts for month-month fluctuations. The average last month reflected a drop of more than 10% from that peak. Separations, too, declined from a July 2006 peak but by just 7% as of last month.

Just as the trend for the monthly employment report – considered the most important government economic data release of the month – has been less than positive, so has the trend of the JOLTS release. Job openings peaked at 4,307,000 in January 2007, plunging almost 16% to 3,626,000 in May.

One problem with the JOLTS data, according to Mike Englund, chief economist of Action Economics, is the volatility of these figures, as economists “have found difficulty correlating [them] with other data.”

But Rick Clayton, chief of the division of administrative statistics at the BLS, notes the JOLTS data does provide a key function as a leading indictor. A reduction in job openings and hirings, he said, typically precedes a weaker labor market. Companies generally cut back on hiring before resorting to downsizing.

Some definitions are in order, According to the BLS, as used in the JOLTS, job openings are “all positions that are open (not filled) on the last business day of the month” which could start within 30 days and is intended to be filled from outside the company. “Hirings,” according to JOLTS, represent newly hired or rehired employees; “Separations” include all employees separated from the payroll during the calendar month who quit, were laid off or discharged or left their job through retirements; transfers to other locations; deaths; or separations due to employee disability.

Not all of the numbers in JOLTS lead to a negative spin. An increase in “quits," for example, the number of workers who leave jobs voluntarily, could be seen as a positive indicator since individuals, for the most part, would not voluntarily leave their jobs unless they were confident of their ability to get a new job.

Beyond the “macro” data describing the overall in's and out's in the labor market, the report details industry hirings, separations and openings with the last serving as an indicator of future expansion.

JOLTS has picked up a following and is part of the Employment Trend Index reported by the Conference Board, which last week forecast more softening to come in the labor market.

A song in the musical “Hello Dolly” noted, “It’s not how you start, it’s how you finish.” In the case of JOLTS, it’s the road you took to get to the finish line.

Mark Lieberman is the senior economist for the Fox Business Network. Prior to joining FOX, he served as first vice president and manager of economic analysis and research at Washington Mutual in New York. Before that, he served as senior vice president at Dime Savings Bank of New York (which was later acquired by Washington Mutual), where he specialized in credit and risk management. He is a member of the Executive Committee of the New York Association for Business Economics. He has a degree in Economics from the Wharton School of the University of Pennsylvania.