Who

The head of Columbia University's Earth Institute, founder of the non-profit group Millennium Promise, author of The End of Poverty, and friend of Angelina and Bono, Sachs may very well be the only economist you've ever heard of.

Backstory

Considering Sachs turned out to be a Harvard economist, it's probably not so surprising to hear he was a math genius as a kid. The son of famous labor lawyer Ted Sachs (who successfully argued several cases before the Supreme Court), Jeff was taking college-level classes in mathematics by the time he'd reached middle school. He later attended Harvard, stuck around to earn a Ph.D. by the time he was 25, and earned tenure three years later. For a decade, Sachs was a Harvard professor, earning recognition as an authority on international macro-economics.

In the mid-1980s he transferred his classroom expertise to the real world when he helped the floundering Bolivian government solve their extraordinary inflation problem. Earning the moniker "Dr. Shock" for his radical approaches to solving serious economic problems, he took his formula on the road, which ended up working in some countries (Bolivia, Poland) but proved substantially less successful in others (such as Russia, where his shock therapy was an out and out disaster). In the late 1990s Sachs retreated to the classrooms of Cambridge, before moving to Columbia in 2002 when he was appointed director of the Earth Institute. He now tackles thorny problems like poverty, HIV/AIDS, and climate change, runs the non-profit Millennium Promise, publishes books, and cavorts with celebs.

Of note

Sachs's goals aren't particularly modest: He's said that by implementing a series of measures—poverty reduction, debt cancellation, and disease control—"we can realistically envision a world without extreme poverty by 2025." It's a bold statement (and, some critics say, a bit naïve) but it's earned him legions of famous fans. Over the last few years, he's become a friend to do-gooder celebrities like Bono (who praised Sachs as "the squeaky wheel that roars") and Angelina Jolie (who traveled to Africa with Sachs and made an MTV documentary about it); raised millions in funding from the richest people in the world (George Soros handed him a check for $50 million in 2006); and earned a spot on the bestsellers list with The End of Poverty.

Of course, Sachs has his share of critics who aren't convinced by his arguments. Some fellow economists have suggested his sweeping reforms are too "one-size-fits-all" to be globally effective and the fact that the $500 billion in aid has already been invested in Africa—with negligible results—is an indication that he may be approaching the issues in sub-Saharan Africa with a bit too much optimism. In one particularly acerbic missive, one of his most vocal critics, NYU professor William Easterly, described Sachs' approach in the Washington Post as "absurd" and "unconvincing." Thesaurus in hand, Sachs replied that Easterly's arguments were "tendentious" and "dystopian."

Personal

Sachs is married to Sonia Ehrlich Sachs, a pediatrician, who refers to herself as a "a happily married single parent" on account of her husband's hectic travel schedule. The Sachses have three children and live on West 85th Street.

No joke

In early 2007, a group dubbed "Sachs for President" took out a full-page ad in the Columbia Spectator urging the economist to run for the highest office in the land, but he's made it pretty clear that he has no intention of ever doing so.