BROOKE GLADSTONE: The saying goes, "You can't be too thin or too rich." Many would quibble with the first part but few, even among the wealthiest Americans, would deny the second. Proof of that can be found in the annual list of the 400 richest Americans tallied by Forbes magazine. Complete with pithy bios and details about whose fortunes have risen or fallen, Forbes crunches the numbers and the ultra-rich position themselves accordingly. But how accurate is Forbes? Timothy O'Brien is a New York Times business reporter and author of a recent book, Trump Nation: The Art of Being the Donald. He's recently written about the Forbes list and Trump's passion for it. O'Brien minced no words in explaining the lure of the list.

TIMOTHY O'BRIEN: It's financial pornography of the most delicious and voyeuristic sort. That's one purpose it serves among the audience out there, the great unwashed among us - [BOTH AT ONCE]]

BROOKE GLADSTONE: [LAUGHS]

TIMOTHY O'BRIEN: - who don't have millions or billions of dollars. But I think for the people on the list, it's a scorecard. And in many ways it remains a very male scorecard. You know, who's the biggest?

BROOKE GLADSTONE: [LAUGHS] So you've written that Trump has taken advantage from the outset of the method that Forbes has used to compile the listing. How is that ranking created?

TIMOTHY O'BRIEN: Forbes looks at the publicly held assets of individuals who have stock in publicly traded companies. That's just a fairly straightforward exercise when you have a Bill Gates whose wealth is tied up in Microsoft, or a Warren Buffet whose wealth is almost solely tied up in Berkshire Hathaway. It becomes a little trickier when you've got somebody like Donald Trump who has wealth and real estate which isn't publicly traded, the valuations are always elastic. And anybody that's based in the private world has a lot of leeway to tell Forbes whatever's on their mind, including how big they think their wallet is.

BROOKE GLADSTONE: But presumably, Trump isn't the only rich guy to verbally declare rather than actually prove his wealth.

TIMOTHY O'BRIEN: I think that's true, and the people who do that are loath to acknowledge it publicly. But I've been covering these guys now for about 15 years, and several of them said often it's hoo-ha, what they tell the magazine.

BROOKE GLADSTONE: [LAUGHS]

TIMOTHY O'BRIEN: Donald himself, in the years when he fell off the list, in the mid-'90s, when he had hit this wall because of gorging on debt that he couldn't repay, Donald himself said, "Every year the Forbes 400 comes out and people talk about if as it were a rigorously researched compilation of America's wealthiest people instead of what it really is, a sloppy, highly arbitrary estimate of certain people's net worth."

BROOKE GLADSTONE: [LAUGHS] That's a pretty disparaging assessment from somebody who you suggest fights tooth and nail every year to get on the list and is absolutely furious when he doesn't get on.

TIMOTHY O'BRIEN: And but, you know, that's vintage Donald. When he's down, he'll tell his critics that their opinions don't matter and when he's up, he desperately courts their good wishes. It's part of his strange ego.

BROOKE GLADSTONE: Well, he does seem to have recognized that there is a certain power to be derived from the list. How has he taken advantage of that cache?

TIMOTHY O'BRIEN: Trump is, you know, a top-tier smoke-and-mirrors man. In the popular imagination, if people think Donald Trump is a billionaire, Donald Trump can then tour the country telling people how they can become billionaires just like him. And investors can be lazy, and if they think someone has credibility, they go ahead and buy the stock.

BROOKE GLADSTONE: And if he is a smoke-and-mirrors man, you also suggest in your book that the Forbes 400 is a smoke-and-mirrors list. And, as a matter of fact, following an article that you wrote in the New York Times in October, Forbes published a response in which it claimed that its estimates on Trump are, in fact, conservative, and they detailed, at least to some degree, calculations of his worth. How did they explain their accounting and what's your response to their response?

TIMOTHY O'BRIEN: They really didn't explain their accounting, you know. And I spent actually a lot of time with their reporter who was working on the piece, and he had no knowledge of Trump's actual history with some of his larger properties in Manhattan. Properties that were in dispute, he made no attempt to speak to the other side. Forbes, in this year's list and last year's, claims that Donald controls 18 million square feet of property in Manhattan, which is an absolute impossibility.

BROOKE GLADSTONE: [LAUGHS]

TIMOTHY O'BRIEN: He just doesn't. And I asked the reporter, "Are you guys going to get into that?" and he said, "No." And I said, "Well, why not?" And he said, "Because my editors told me not to." If they really dig into it and really do due diligence, they're going to understand how severely they've been spun by Donald.

BROOKE GLADSTONE: So since we know now how Donald derives some value from the list, what sort of value does the list derive from listing Donald?

TIMOTHY O'BRIEN: Well, you know, what's very interesting is this year I think they had pictures of maybe four or five, quote, unquote, "billionaires" associated with the list, and Donald's was one of the biggest pictures they had on the list - [OVERTALK]

BROOKE GLADSTONE: [LAUGHS]

TIMOTHY O'BRIEN: - even though he ranks on their list in the 80s. And that's because Donald Trump is a very recognizable business figure. I think Gallup did a survey around the year 2000 of the most recognizable or famous businesspeople in the United States, and Trump was number one.

BROOKE GLADSTONE: So Donald brings sex to the Forbes list.

TIMOTHY O'BRIEN: And marketability.

BROOKE GLADSTONE: But, as you've written, despite its prestige, not everyone wants to be on that list. Why don't they? And who are these people who think they're too good for the Forbes 400?

TIMOTHY O'BRIEN: Well, you know, people who are really secure in their identity and secure with who they are as people don't need to walk around proclaiming publicly how much they're worth. And the reason Donald does it is because he's an amazingly insecure person. In the book I quote Nelson Bunker Hunt. When Hunt was being grilled by Congress about his net worth, he said, "A fellow asked me that once and I said, 'I don't know.' But I do know people who know how much they are worth generally aren't worth much."

BROOKE GLADSTONE: So the Forbes 400 really isn't for the rich. It's really for the rest of us and Donald Trump.

TIMOTHY O'BRIEN: That's absolutely right.

BROOKE GLADSTONE: Timothy, thank you very much.

TIMOTHY O'BRIEN: Thanks, Brooke.

BROOKE GLADSTONE: Timothy O'Brien is a business reporter for the New York Times and author of Trump Nation: The Art of Being Donald. [MUSIC UP AND UNDER]

BOB GARFIELD: Coming up, when it comes to memoirs, there's the truth and then there's - "truthiness."

BROOKE GLADSTONE: This is On the Media from NPR. (FUNDING CREDITS) END SEGMENT B STATION BREAK 2 (MUSIC)