Welcome to March Madness, an annual rite of spring, where businesses decry the billions of dollars in lost productivity as workers cheer on their favorite college basketball teams and check their office pool instead of filing that overdue report.

But in an era of full employment and smartphone streaming, some employers are taking a different approach: Put the games on big screen TVs, serve up some pizza and embrace the Madness.

“Everybody is doing it — watching the games — and everybody is in a pool,” said Tom Gimbel, founder and CEO of LaSalle Network, a Chicago-based staffing and recruiting firm. “The more the boss tries to hide it, the more people want it.”

Celebrating the tournament — which culminates April 8 at U.S. Bank Stadium in Minneapolis — may be a long-term win for recruitment, but with more than 75 million employees spending 6.4 hours of work time watching basketball, it is projected to cost employers nearly $13.3 billion in lost productivity this year alone, according to Chicago-based outplacement firm Challenger, Gray & Christmas.

Productivity is not the only item in the March Madness cost-benefit analysis, however.

“It is an enormous cost, but at the end of the day, trying to ban March Madness activities from the workplace would cost employers far more in employee morale, camaraderie and culture, which is particularly important when the labor market is really tight and companies are fighting to retain and attract the best people,” said Andrew Challenger, the outplacement firm’s vice president.

Companies’ willingness to embrace events like the Final Four is rising each year, said Marilyn Bird, the Chicago-based district president of staffing firm Robert Half.

LaSalle Network was an early adopter. It plays host to an annual March Madness office party on the first Friday of the tournament, inviting hundreds of clients and employees to don their favorite college sweatshirt and enjoy the games on 10 flat screen TVs, with a hot dog cart, kegs and other decidedly nonbusiness amenities on hand.

The epiphany for Gimbel came about 10 years ago, when he learned to stop worrying about employees slacking off during the tournament.

“It hit me once, wait a minute — let’s go all in on this, let’s really enjoy it,” Gimbel said.

Integrated Project Management, a Chicago area consulting firm, has been hosting its own March Madness viewing party for six years. A conference room is converted into a sports bar on Friday, where a 70-inch TV usually reserved for PowerPoint presentations instead streams the games. Smaller TVs dot the room for alternative games.

Pizza and wings are served at lunchtime, and the conference room is usually packed with more than half of the firm’s 100 Chicago-area employees.

“We get a pretty big turnout for this,” said Amber Selman, 32, a project management consultant who has organized the March Madness viewing party since its inception.

With legalized sports betting coming to a number of states, watching the games could become even more of an office distraction — or perk, depending on how it’s viewed — in the years ahead.

This year, 47 million American adults are projected to bet $8.5 billion on the NCAA men’s basketball tournament, according to a survey released Monday by the American Gaming Association.

More than half of that action — $4.6 billion — will be placed in 149 million brackets, including office pools.

The other $3.9 billion of March Madness wagering funnels mostly through illegal channels such as bookies and offshore gambling sites, but legal sports betting is on the rise after a Supreme Court ruling last year opened it up beyond Nevada to all states.

Bettors in Delaware, New Jersey, Pennsylvania and a handful of other states will be able to wager legally on March Madness games this year, with Illinois among dozens of states that could be in the game by 2020.

If all 50 states allowed legal sports betting this year, total wagering on March Madness would nearly double, topping $15 billion, according to Eilers & Krejcik Gaming, a California-based research and consulting firm.

In some cases, employers, such as accounting firm BKD, run their own “non-gambling” office pool.

BKD, which has offices in Chicago and suburban Oakbrook Terrace, has a variety of March Madness-related activities, including TVs in the lunchroom tuned to the games, an ice cream party on Friday afternoon, and a Saturday viewing event catered by Portillo’s, when most of the firm’s accountants are in the office during tax season.

“We do activities for employees during this week to build morale and have some fun, especially during our busy season,” said Valerie LaMorte, human resources manager at BKD in Chicago. “We’re an accounting firm so it’s a crazy time.”

On Monday, BKD also opened up its official company bracket to all employees. There is no entry fee, everybody participates, and employees are encouraged to follow along as the games play out.

The grand prize is a $25 gift certificate.

“It’s nothing significant — more the bragging rights,” LaMorte said.

Not all companies are so forward thinking. The NCAA created a “boss button” so that viewers streaming games could toggle to a faux spreadsheet when prying eyes got to close to their computer screen.

But the proliferation of smartphones makes streaming the games a relatively unobtrusive activity for any employee, and a bad bet for employers to try to suppress it.

“I think there’s just a can’t beat them, join them attitude, and a lot of companies are embracing the tournament in the workplace and I think that’s a really smart move,” Challenger said.