The missing piece may be falling into place for the U.S. economy.
Housing-related employment -- anemic throughout much of the current expansion -- got a jolt in January. That's unusual, since bad weather tends to make it one of the weaker months for construction hiring.
But last month the number of residential construction workers rose 12,500, a gain of 1.8 percent, the biggest one-month jump in percentage terms since 2002.
Other categories related to housing jobs also showed strength. Specialty trade contractors, who've been in short supply, increased by 7,600 to the highest level since 2009. Wood products manufacturers added 4,100 employees, building materials stores another 3,700.
Architectural and engineering employment, which includes home designers, increased by 7,800 to the highest level since 2008. And as more homes get built, more realtors will be there to help sell them. Real estate employment rose by 4,400.
"If there is an industry that has an opportunity to surprise" in 2015, "it is residential real estate," said Neil Dutta, head of U.S. economics at Renaissance Macro Research in New York. "We see strong growth in housing and construction-related industries for both white-collar and blue-collar workers."