World Economic Forum 2019: What to expect from this year's summit in Davos It's a gathering for the world's business and political leaders.

LONDON -- The world’s most rich and powerful business and political leaders will descend on Davos, Switzerland, on Tuesday, as the annual gathering of the World Economic Forum begins.

The annual summit in the Swiss Alps takes place over four days. Celebrities, academics and members of the media are often invited to promote causes they support.

President Donald Trump was the main attraction in 2018 but will not be attending this year.

“Out of consideration for the 800,000 great American workers not receiving pay and to ensure his team can assist as needed, President Trump has canceled his delegation’s trip to the World Economic Forum,” White House press secretary Sarah Sanders said in a statement.

Who’s going?

This year’s summit may be more notable for who isn’t attending rather than who is. French President Emmanuel Macron and British Prime Minister Theresa May have also pulled of the forum due to domestic crises.

May is locked in Brexit negotiations while Macron is busy steadying the ship as the Gilets Jaunes protests enter their tenth weekend.

A number of famous faces, however, will be present. Prince William is expected to talk about mental health. The prime minister of New Zealand, Jacinda Ardern, will address a “range of topics” and Sir David Attenborough will discuss biodiversity. They will be joined by Winnie Byanyima, head of Oxfam International, and Rwandan President Paul Kagame.

Also attending is Brazil's new president, Jair Bolsonaro.

Around 60 percent of Davos attendees will be representatives of the World Economic Forum’s major donors – known as “industry affiliates” – according to Professor Adrienne Sörbom, author of "Discreet Power: How the World Economic Forum Shapes Market Agendas." You can see the full list of industry affiliates here.

The process of choosing who will be invited to the forum is complicated, as members “haggle” over who to invite for months.

“This is something they are working on all year,” Sörbom told ABC News. “There is constant haggling within the organization [about] who to invite. Everybody who works within the World Economic Forum has their own [individual] interest" though the broad aim is to secure people from “all walks of life.”

The forum has been criticized for being out of touch, according to IHS Markit economist and 10-time attendee Nariman Behravesh.

“In terms of economists there are about half a dozen that they keep inviting back,” he told ABC News. “There are a lot of really good economists in the U.S. and the U.K. and elsewhere that don’t get invited. I don’t really understand why they bring people to say essentially the same thing they said the last year and the year before.”

The World Economic Forum is an exclusive affair and tickets often cost thousands of dollars. It's also been accused of “serving the elite,” according to Behravesh.

"They’ve tried to move away from that, but not terribly successfully one has to say,” he added.

What do they do?

The official engagements take place in the lecture-hall like rooms of the conference center, but most of the business that is conducted occurs in private meetings. The bars, restaurants and cafes of Davos play host to most of these meetings.

“Davos is a fairly small town,” Sörbom said. “During this week it is totally occupied by the World Economic Forum. It’s not lobbying, and it’s not business, but it is a way of making politicians and business people find each other more easily.”

Those with primarily business interests will meet with one another, while politicians are more likely to engage in a kind of “informal diplomacy,” she said.

According to Behravesh, “The private sessions are more interesting. My company is holding one. There you get a much more open dialogue, a discussion among CEOs – a lot of chit chat in the hallways. That exchange is very valuable.”

This year, the focus is on technology. The theme is “Globalization 4.0: Shaping a Global Architecture in the Age of the Fourth Industrial Revolution.” While the central mission of the World Economic Forum is to promote free trade, in recent years issues like the environment, poverty and worldwide hunger have entered the agenda.

“The ideology of the World Economic Forum has changed over time,” according to Sörbom. “They were promoting [free trade and globalization] in the early 1990s.”

Now, the policy is more social oriented. “You can’t have economic development without social development,” she noted. “It’s a truly liberal organization.”

What to expect?

“Certainly the mood will be a lot darker [than last year],” Behravesh said. “[Attendees] are worried about the stock market. But I think they’re much more worried about growth slowing in most parts of the world, in particular China. So those are the things that are on their mind.”

Despite the gloom, he believes world markets are not quite on the verge of a global recession.

“The chances of a recession this year are still relatively low,” he said. "And the reason we say that is that the policy environment is still quite accommodative to growth.”

Do we need the World Economic Forum?

While the forum may be helpful in setting a general agenda, the jury is still out over how much influence it actually has.

“They’re not going to be able to reign in Donald Trump’s protectionist tendencies – that’s just not going to happen,” Behravesh said. “But they could provide a forum of discussion on the benefits of globalization."

He continued, “As to how much influence they have on, whether it’s Donald Trump, or the Leavers in terms of Brexit, or the Italian populist coalition, or the Yellow Jackets, I don’t think they’re going to have much influence. Partly because they’re viewed as not representing the people who are left behind, to put it bluntly. It’s a very risky situation – let’s hope the world leaders don’t mess it up.”