Even if Friday’s jobs report is great, don’t get too excited

Economists expect the jobs report on Friday to show that 180,000 jobs were added to nonfarm payrolls in July, according to Thomson Reuters. That's a distinct improvement from the shocking 11,000 jobs added in May but well off from the average rate for the U.S. economy in the previous two years, which is around 240,000.

Is this slowdown a symptom of broader macroeconomic weakness?

Looking at other labor-market indicators does not provide a clear resolution. Some of them (such as initial and continuing unemployment claims) have been low and stable in the past few months, while others (such as the percentage of workers reporting they are working part time for economic reasons) show evidence of cooling off. A useful summary indicator is the broad-based aggregate Labor Market Conditions Index published by the Federal Reserve. This series has shown a decline every month since January, lending some credence to the weakness story.

The headline numbers also mask a much more dramatic slowdown in some parts of economy, most notably in the goods-producing sectors. This is being offset by steady growth in the service sector, so the aggregate numbers still show net job gains. During the first six months of 2016, employment in the goods-producing industries was almost flat (and even contracted by some measures) while private service-producing industries expanded payrolls by an annualized rate of 2 percent, roughly on par with the growth rate in 2014 and 2015. But, even within the service sector, there are large differences across industries.

These patterns point to other, somewhat longer-term/structural, forces underlying the persistent weakness in the labor market.

Economists often use the Beveridge Curve – the empirical relationship between job openings (or vacancies) and unemployment rates – as an indicator of the efficiency of the labor market. Since the onset of the Great Recession, this relationship has suggested a deterioration – given the number of available job openings, the unemployment rate is still too high relative to historical patterns.

One potential explanation is a mismatch between the types of jobs available and those that job seekers are looking for.

Another possibility is that firms are not trying very aggressively to fill their job openings. Such cautious behavior is also evident in the behavior of business investment, perhaps reflecting long-lasting effects of the financial crisis. While these forces are unlikely to significantly change month-to-month payroll and unemployment numbers, they do indicate that this recovery faces a greater likelihood of running out of steam, at least in the medium term.

The labor-market situation has become more uncertain and will likely push the Fed towards making its monetary policy adjustments even more gradually. Even if Friday's report surprises on the upside, the picture is unlikely to change drastically.

Commentary by Vaidyanathan ("Venky") Venkateswaran, who joined the New York University Stern School of Business as an assistant professor of economics in July 2013. His research focuses on the role of information in macroeconomics. The recipient of several fellowships and awards, including the Departmental Excellence Award at the University of California Los Angeles in 2007-08 and 2008-09, Prof. Venkateswaran has worked as an assistant professor of economics at Pennsylvania State University, and earlier as vice president of fixed income research at Lehman Brothers.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.