DAVOS, Switzerland -- Leaders in business, finance and government have gathered here every winter for the past four decades to talk about international economic cooperation, the theme of the annual conference known as the World Economic Forum.

In one important respect, this theme has always been at odds with Swiss policy. The forum's hosts have an old and well-deserved reputation for operating some of the most secretive banks in the world. Critics say the Swiss system has allowed foreign clients to avoid paying taxes and to conceal ill-gotten gains, undermining public finances and the rule of law globally.

So it was no surprise when things got heated during a panel on tax policy at this alpine result Thursday, when Winnie Byanyima, the executive director of Oxfam International, called Switzerland "a notorious tax haven."

Swiss banks have recently had competition from other international tax havens such as Singapore, Panama and the Cayman Islands, but they still manage about $2.3 trillion of foreign wealth. That is about a third of all wealth held in foreign accounts worldwide, according to an analysis of official Swiss data by Gabriel Zucman, an economist at the University of California, Berkeley.

"Historically, Switzerland has been the No. 1 tax haven," Zucman said. "Swiss banks still play an important, very nefarious role."

Policymakers here say that is changing. When the forum meets next year, Swiss banks will have begun sharing information on their clients with foreign authorities in a few dozen countries in accordance with a new protocol established by Organization for Economic Cooperation and Development.

The organization's secretary general, Angel Gurría, told the audience in Davos that, with the new policy,  Switzerland is now an "exemplary" actor in international tax enforcement. Swiss policymakers, he said, "joined the fray and now they're fighting the good fight."

Although Switzerland may be in compliance with its international obligations, critics such as Oxfam's Byanyima still say that reform is too slow. Many countries began exchanging information under the agreement this month, and Switzerland does not yet have agreements with many developing countries on sharing data, so the wealthy in those nations will be able to continue concealing their wealth from local authorities for now.

"It’s true that they’re taking some steps to align themselves with the European rules," Byanyima said of the Swiss. "We recognize the progress that’s been made, but it’s not deep enough. It’s not fast enough."

Zucman, the economist, agreed. "The pattern here is that Switzerland just tries to drag its feet," he said.

From the Swiss point of view, there are reasons for the delay. The country's unusually complicated constitution makes legislation a tedious process and often requires that the whole country vote to approve major changes.

Those political factors explain why Switzerland will need to use most of the time allowed under the internationally negotiated deadline, wrote Daniela Lüpold, a spokeswoman for the Swiss Bankers Association, in an email.

In poor countries, secret bank accounts not only deprive governments of urgently needed revenue, Zucman said. They can also abet corruption by enabling well-connected officials to hide bribes and embezzled funds from investigators, preventing policymakers from establishing the kind of reliable, transparent governance that many economists say is crucial for economic growth.

Finally, Zucman noted, since it is primarily wealthy households that find ways of avoiding taxes, secrecy in banking exacerbates wealth inequality.

Swiss President Doris Leuthard herself argued that economic fairness should be a priority for the global elite in one of the conference's introductory speeches on Tuesday.

"We’ve got to find strategies so that the sharp divide between rich and poor doesn’t get larger, and we don’t see increasing strain placed on social peace," she said.

"President Leuthard is satisfied with Swiss progress toward greater financial transparency," spokeswoman Brigitte Hauser-Süess said in a statement to The Post Thursday.

More from Wonkblog: