From teachers walking out of classrooms in several states to hospital workers manning picket lines in California, a surge in strikes is happening in 2018. As many major work stoppages had taken place by the end of March as occurred during all of last year.

The recent spike follows a relatively placid period on the labor front. The U.S. Department of Labor counted seven stoppages of 1,000 or more workers and lasting at least one shift in 2017, making it the second-lowest number recorded in a year, and fewest since 2009, when the department counted five such strikes.

Strikes idled 25,000 workers last year, the second-lowest annual count since 1947. Among those were walkouts of 15,000 information industry workers, including a long-running labor dispute between Charter Communications (CHTR) and 1,800 union members and another strike lasting one day by 13,200 AT&T (T) employees.

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But the first three months of 2018 have seen revived activity on the labor front, and the second quarter is suiting up to be active as well, as workers strike over issues including pay, benefits -- and in the case of some educators -- distress over lack of funds for equipment and supplies.

Nearly 37,000 workers were involved in two large strikes in February, while January had the 1,800 Charter employees idle. In all, seven large work stoppages occurred in the first quarter.

In March, 42,000 workers participated in four strikes, including the continuing year-long walkout at Charter and 1,400 Frontier Communications (FTR) workers in West Virginia and Virginia, according to government data. In addition, 35,000 elementary and middle school teachers in West Virginia and another 3,800 in New Jersey walked off the job in March.

The trend persisted in May, with about 53,000 hospital workers hitting the picket lines on Monday at the University of California. Nurses will strike in support on Tuesday and Wednesday. The union members are reportedly seeking pay hikes of 6 percent and a freeze on health care premiums, and they've rejected a 3 percent wage increase offer.

In Pueblo, Colorado, nearly 1,000 public educators walked off the job on Monday in what the Denver Post said was the state's first teacher's strike since 1994. They're demanding a 2 percent wage increase and improved benefits.

Worker unrest isn't solely about wages, yet the fact that American paychecks have expanded at a snail's pace surely fans the flames. American wages grew a tepid 2.6 percent year-over-year, according to Friday's jobs report. That amounts to an additional $230 a year for the average worker, and it's far below what economists believe the U.S. should be seeing, given today's tight job market.

Cuts in state funding have hammered public education, with per-student spending down 15.6 percent since 2008 in K-12 schools in Oklahoma, according to the left-leaning Center for Budget and Policy Priorities. All told, 29 states have cut school funding during that time, according to its analysis.

Retirement benefits are also an issue. For instance, Kentucky lawmakers considered ending the state's existing pension plan for future teachers in the face of the state pension system's unfunded liability of $40 billion.