Larry Lopez, president of construction staffing service Green JobWorks in Baltimore, Maryland, needs about 20 skilled workers — a tall order for any small employer in a tight labor market. But even available workers often lack the experience he needs, Lopez says.

"A lot of clients are asking for people who can operate tools like chipping hammers and saws. And the folks that are unemployed and coming into the industry, they find themselves without a lot of experience," Lopez said. "It's difficult because they don't have the skills necessary to perform for our customers."