The State of the Unions from Marketplace. I'm Sabrie Benashore, in for David Brancaccio.

U.S. markets are closed today in honor of Civil Rights icon Martin Luther King Jr's birthday markets reopen tomorrow Tuesday

930 a.m. Wall Street time. In 1968 Martin Luther King Jr. was assassinated

after speaking with striking sanitation workers in Memphis. was assassinated Cornell University shows that over the last two years strike activity has been picking up.

Marketplace's Justin Ho has more.

A lot of the big strikes last year were against big employers,

Hollywood Studios, the big three automakers.

But Kathy Creighton at Cornell University

says many of them were against smaller employers.

Restaurants, higher education, warehouse workers,

a lot of teachers and public sector workers.

And those workers watched last year as the big strikes won big concessions from studios and automakers.

Jake Rosenfeld, a professor at Washington University in St. Louis,

says those wins create momentum. We know from past research that successful strikes

prove contagious. They tend to lead to other strikes.

Workers know that going on strike comes with the risk of job loss, but Rosenfeld says they also know they have options, considering how tight the labor market is right now.

It grants them the freedom to take risks at work,

such as participating in a strike or threatening to unionize

without the fear that such activity could lead to a prolonged period of joblessness.

And as long as the unemployment rate stays low, Rosenfeld says strike activity will likely

keep up.

I'm Justin Howe for Marketplace. And the Workers have had it okay in recent years. Some 2.7 million jobs were created last year and the

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