Any given day might find Roubini in a different time zone or a different continent, whether at a business meeting in Europe, a Congressional hearing in Washington, D.C., or the occasional eyebrow-raising party at his own spacious city loft.
So what's with the morbid nickname? It has to do with Roubini's prescience: Two years ago, the economist and New York University professor predicted a severe U.S. recession, triggered by a giant housing slump and exacerbated by rising oil prices and rising debts.
"This is a tipping point for the U.S. consumer," Roubini wrote in late August, 2006, "and the effects will be ugly."
Days later, he shared his forecasts in a speech before economists at the International Monetary Fund. He predicted the downfall of subprime mortgage lenders and the risks to U.S. mortgage giants Fannie Mae and Freddie Mac, to banks and, ultimately, to the world economy.
"I started talking about subprime mortgages being a problem when 99 percent of the world had never even heard the word subprime," Roubini said in a recent interview with ABCNews.com.
"At the time, people thought I was crazy," he recalled.
To be sure, Roubini wasn't the only economist to warn of a housing bust and related consequences.
But "the bulk of the people in the audience at that point were not where Nouriel was," said Prakash Loungani, the IMF research advisor who invited Roubini to speak. "They thought what he was describing was something out in the left field."
Don't expect economists who doubted Roubini to concede that they were wrong, Loungani added.
"Economists don't come out and say these things," he said. "I think it's reflected just in the respect and the following he has now. That's where you see the shift."
Not a 'Permabear'?
Still, not everyone is convinced of Roubini's prognostication skills. Kenneth Rogoff, an economics professor at Harvard who has known Roubini since he was a grad student, said Roubini has been pessimistic about the economy for a long time.
"He provides a lot of value-added [analysis] because he's looking at dark scenarios and what could happen and how it could happen," he said.
But, he said, "I don't think the point is that he called the recession, because he's called the recession repeatedly for many years."
Roubini dismisses the idea that he is a "permabear" -- economist slang for someone who systematically projects downturns -- just as he dismissed skepticism about the dire predictions he made two years ago.
"When there is a bubble, there is euphoria and irrational exuberance and people lose track of the overall underlying fundamentals," he said. "I was comfortable with the rigor of my analysis."
After a decade spent studying financial crises in emerging markets, Roubini was able to draw parallels between emerging market countries and the well-established U.S. economy through everything from housing and credit bubbles to enormous deficits.
The United States, Roubini told the New York Times in August, "looked like the biggest emerging market of all."
His work, he said, is holistic in that he relies not just on statistical models but also on empirical experience and history.
Roubini's own history is as complicated as some of his analysis.
The son of an Iranian-Jewish Persian carpet exporter and a homemaker, Roubini lived in three different countries before the age of 5. He was born in Turkey while his parents were there on business, later moved to Tehran and then Tel Aviv, Israel before his family -- Roubini is the oldest of four -- finally settled in Italy.
The 'Little Geek'
It was as a young teenager that Roubini discovered his interest in economics.
"I was already a little geek by the age of 14 or 15," he said.
After graduating college in Italy, Roubini moved to the United States to pursue a h.D. at Harvard University, where he studied under noted economists Jeffrey Sachs and Lawrence Summers, who later served as Treasury Secretary under President Clinton and has been named as a candidate to fill that post again in the Barack Obama administration.
Roubini began his own teaching career at Yale University, where he worked as an assistant professor before transferring to become a tenured professor at NYU's Stern School of Business. For two years, he left his NYU post for D.C., first to work at the White House Council of Economic Advisers and then to join Summers at the Treasury Department.
Along the way, he started an economics blog that grew to become a full-blown business: In addition to its economic analysis subscription service, RGE Monitor -- short for Roubini Global Economics -- advises private and public sector clients around the world.
Today, RGE business accounts for much of Roubini's global travels -- "In the next few weeks I'm going to be traveling to France, Germany, Switzerland and Spain and spending Thanksgiving in Russia, of all places," he said recently -- which he balances against his NYU teaching schedule, economic conferences, speaking engagements and, last but not least, a busy social calendar.
Though Roubini works 12 hours a day, the great thing about New York, he said, is that after work there's always a gallery opening, a museum event, a dinner party or a banquet to attend.
But his social outings have recently garnered Roubini some unwelcome media attention that has evolved into a bizarre feud with the editor of a gossip Web site.
The Birth of Dr. Boom?
Nicholas Denton, the founder of Gawker.com, recently wrote a post labeling Roubini, who is single, as a playboy, citing the numerous party pictures of a smiling Roubini posted on the social networking Web site Facebook. Gawker also published a message that Roubini wrote to a woman, joking about a decadent vacation in St. Tropez and inviting her out for drinks.
The Gawker posts prompted an angry response from Roubini, who excoriated Denton by posting messages on Denton's own Facebook page, accusing him of "Nazi-style anti-Semitism."
Neither man will comment on the situation, but Roubini says he stands by his posts on Denton's page. He is also unapologetic about his social life.
"I don't stay home," he said. "I have a life."
The cheery face that Roubini wears at social gatherings may be finding its way into his professional life … at least a little.
His predictions for the economy remain dire -- he expects an 18- to 24-month-long recession, far longer than the typical 8-month U.S. downturn. But he believes that a range of measures, from more government spending on infrastructure to more money for banks to a temporary freeze on foreclosures, could allow the country to avoid an even more severe financial crisis.
And he doesn't think the nation is headed toward another Great Depression.
"I'm sure we'll get out of it," Dr. Doom said.
"A year and a half from now when things are changing," he added, "I might be Dr. Boom."