After eleven million documents were leaked from the law firm Mossack Fonseca, observers are wondering why the company’s roster of tax dodgers and money launderers does not seem to include more American citizens. Photograph by Rodrigo Arangua / AFP / Getty

Who is the odd person out from this list: Ayad Allawi, King Salman bin Abdulaziz, Bashar al-Assad, David Cameron, Sigmundur Davíð Gunnlaugsson, Mauricio Macri, Lionel Messi, Sheikh Khalifa bin Zayed al-Nahyan, Marianna Olszewski, Petro Poroshenko, Vladimir Putin?

If you picked Olszewski, you’re right. In the initial wave of stories about Mossack Fonseca, the Panamanian law firm whose internal documents—2.6 terabytes' worth—were leaked by an anonymous source to the German newspaper Süddeutsche Zeitung, she was about the only American citizen I saw mentioned. The leaked documents, which Süddeutsche Zeitung shared with the International Consortium of Investigative Journalists (I.C.I.J.), a New York-based public-interest organization, reveal that family members, associates, and financial advisers of some of the world’s most powerful people enlisted Mossack Fonseca’s services to set up offshore shell companies, which can be used to hide money and assets from the prying eyes of tax inspectors and other government agencies.

According to a report by the BBC, Olszewski, a thirty-nine-year-old investment adviser and the author of the book “Live It, Love It, Earn It: A Woman’s Guide to Financial Freedom,” also had dealings with Mossack Fonseca. The BBC story alleges that the law firm created an elaborate scheme to help Olszewski retrieve $1.8 million that she had invested in an offshore vehicle, without revealing her identity to the bank that was holding the funds. (Mossack Fonseca told the BBC, “Your allegations that we provide structures supposedly designed to hide the identity of the real owners are completely unsupported and false.” Olszewski did not respond to the BBC’s requests for comment, or to mine.)

The BBC story illuminated the fact that much of the work done by firms like Mossack Fonseca involves people who aren’t particularly well known, and sums of money that aren’t huge. Moreover, the use of offshore accounts can be perfectly legal, and Olszewski’s financial affairs would appear to be of no great import to anyone but herself and the Internal Revenue Service. She doesn’t really belong on a list of prominent names associated with the leak, alongside the leaders of Argentina, Iceland, Russia, Saudi Arabia, Ukraine, the United Arab Emirates, and the United Kingdom. But why weren’t more Americans named?

One possible explanation, which we can dismiss immediately, is the notion that this sort of thing couldn’t happen here. To the contrary, the United States is widely recognized as a leading source of offshore money: during the Union Bank of Switzerland tax-evasion scandal, it emerged that, at that bank alone, U.S. clients had almost twenty thousand Swiss-based accounts. In the hedge-fund industry, it is considered perfectly normal and entirely legitimate to domicile funds in tax havens like Grand Cayman or the British Virgin Islands. In addition, as Bloomberg’s Jesse Drucker reported earlier this year, America is also, thanks to its relatively lax disclosure laws, emerging as a major tax haven and destination for offshore funds. Anonymous money is moving in and out of the United States all the time, with American lawyers and financial intermediaries helping to facilitate the flow.

A more convincing explanation is that the journalists who are researching the leaks are still pursuing American clients of Mossack Fonseca. In fact, we now know this to be the case. On Monday, a piece published by Fusion, one of the U.S. media organizations that has access to the leaked material, said, “So far, the International Consortium of Investigative Journalists (ICIJ) has only been able to identify 211 people with U.S. addresses who own companies in the data (not all of whom we’ve been able to investigate yet). We don’t know if those 211 people are necessarily U.S. citizens. And that figure covers only data from recent years available on a Mossack Fonseca internal database—not all 11.5 million files from the leak.”

In an article published on Monday evening, McClatchy, another news organization working with the I.C.I.J., identified more American citizens for whom Mossack Fonseca registered offshore companies. The people named didn’t include any politicians or other well-known figures. “Some appear to be American retirees purchasing real estate in places like Costa Rica and Panama,” the McClatchy report said. But it also mentioned at least four people who have been charged with serious financial crimes: Robert Miracle, of Bellevue, Washington, who was convicted of running a sixty-five-million-dollar Ponzi scheme;** ** Benjamin Wey, the president of the New York Global Group, who was indicted last year on charges of securities fraud (his lawyer denied the charges in an e-mail to the Times); Igor Olenicoff, a Florida real-estate mogul, who was convicted of tax evasion in 2007; and John Michael (Red) Crim, a financial adviser from Pennsylvania, who was convicted in 2008 of plotting to help people evade taxes.

So much for individuals. What about U.S. banks, financial advisers, law firms, and other intermediaries? Data compiled by the I.C.I.J. consortium indicates that, of the roughly fourteen thousand intermediaries—banks, law firms, company-incorporation firms, and other middlemen—with which Mossack Fonseca worked over the years in order to set up companies, foundations, and trusts for its customers, six hundred and seventeen were based in the United States. That’s a lot.

On the other hand, other countries appear to have provided Mossack Fonseca, which has thirty-six offices on three continents, with much more business than America did. In the past, the firm had at least one office in the United States—in Las Vegas—but it doesn’t currently have any. According to charts published by the I.C.I.J., the United States isn’t among the ten countries for which Mossack Fonseca created shell companies. (Hong Kong, Switzerland, and the United Kingdom held the first three places). And no American banks appear among the list of the ten financial intermediaries that most often requested offshore companies for their clients.

There are several reasons why the United States might not have been a major source of clients for the Panamanian law firm, relatively speaking. Perhaps it deliberately avoided having a large presence in the United States, so as not to attract the attention of U.S. authorities. Or perhaps there was too much competition. An article published in The Economist in 2012 pointed out that the business of setting up shell companies in tax havens is competitive and includes a number of well-established firms, such as the Hong Kong-based Offshore Incorporations Ltd., the Isle of Man-based OCRA Worldwide, and Morgan & Morgan, of Panama. In other words, wealthy Americans have many options for structuring their offshore holdings.

Eoin Higgins, a writer from Massachusetts, suggested another possible factor as well: the diplomatic relationship between Washington and Panama. In many cases, the entire point of setting up a shell company is to hide things. But, in 2010, the United States and Panama signed a trade-promotion agreement that, among other things, obliged Panama to provide to the U.S. authorities, on request, “information regarding the ownership of companies, partnerships, trusts, foundations, and other persons, including . . . . ownership information on all such persons in an ownership chain.” Higgins pointed out, “If Panama had ever been an attractive destination for American offshore storage of funds, this agreement shut the door on that possibility.”

Going forward, more Americans may well be named in stories arising from the leak. In the meantime, at least one observer, Craig Murray, a former British diplomat, has suggested that the journalists investigating the leak may be overemphasizing the role of non-Western figures, such as Putin and Assad. “What if they did Mossack Fonseca searches on every listed company in the western stock exchanges, and on every western millionaire they could trace?” Murray wrote in a blog post on Monday. “That would be much more interesting. I know Russia and China are corrupt, you don’t have to tell me that.”

Murray’s last point is well taken. But crony capitalism and tax evasion are huge problems for poor and middle-income countries: according to the International Monetary Fund, it costs them hundreds of billions of dollars in tax revenues each year. In detailing how this process works, the Panama Papers stories that have been released thus far have already performed an important public service. And the journalists have already netted some Western figures, including Gunnlaugsson, the Icelandic Prime Minister, and Ian Cameron, the late father of David Cameron, the British Prime Minister. Gunnlaugsson resigned on Tuesday, while 10 Downing Street is refusing to say whether the Cameron family still has any money in offshore tax havens.

In response to speculation about the dearth of American names, Stefan Plöchinger, an editor at Süddeutsche Zeitung, said in a tweet on Monday, “Just wait for what is coming next.” After other reporters picked up on this message, Plöchinger clarified that he wasn’t referring specifically to the United States. “No, it just means: relax,” he said. “What’s in the files will be published without fear or favor.”