The December jobs report was somewhat of a disappointment, with America’s total number of non-farm payroll jobs rising by only 148,000. That may seem like a big gain, but economists polled by Reuters had predicted an increase of 190,000.

“An unexpected loss of 20,000 retail positions during the holiday season held back the headline number,” explains CNBC analyst Jeff Cox.

Still, the overall economic picture remains mostly bright. As RSM US chief economist Joseph Brusuelas told the Wall Street Journal, “Recent economic data ‘all point to an economy that has shifted into third gear in front of a large corporate tax cut that figures to turbocharge growth in the near term despite the modest deceleration in the pace of hiring in December.’”

In my view, the most encouraging number in the December jobs report was the labor-force-participation rate (LFPR) among men aged 25 to 54, which reached 89 percent for the first time since 2011, up from 88.5 percent in November.

By way of perspective, the LFPR among prime-age men had never once fallen below 89 percent until December 2009. When the Great Recession began, in December 2007, it stood at 90.9 percent. When George W. Bush first took office, in January 2001, it stood at 91.7 percent. When Ronald Reagan first took office, in January 1981, it stood at 94.2 percent.

If you believe, as I do, that the long-term decline of work among prime-age men is a genuine social crisis, then the news from last month is worth cheering. Of course, we don’t know whether it represents a sustainable increase in the prime-age-male LFPR or just a temporary blip in the data. But for now, at least, it’s a promising development.