David Kestenbaum

David Kestenbaum is a correspondent for NPR, covering science, energy issues and, most recently, the global economy for NPR's multimedia project Planet Money. David has been a science correspondent for NPR since 1999. He came to journalism the usual way — by getting a Ph.D. in physics first.

In his years at NPR, David has covered science's discoveries and its darker side, including the Northeast blackout, the anthrax attacks and the collapse of the New Orleans levees. He has also reported on energy issues, particularly nuclear and climate change.

David has won awards from the American Association for the Advancement of Science, the American Physical Society and the Institute of Electrical and Electronics Engineers.

David worked briefly on the show This American Life, and set up a radio journalism program in Cambodia on a Fulbright fellowship. He also teaches a journalism class at Johns Hopkins University.

David holds a bachelor's of science degree in physics from Yale University and a doctorate in physics from Harvard University.

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Planet Money
6:08 pm
Thu June 5, 2014

Why A Pack Of Peanut Butter M&M's Weighs A Tiny Bit Less Than A Regular Pack

Peanut Butter M&M's are larger and more irregular than standard M&M's.
Quoctrung Bui/NPR

Originally published on Wed June 25, 2014 5:03 pm

The other day I went down to the little shop in the lobby of our building for a snack. I couldn't decide whether I wanted regular M&M's or Peanut Butter M&M's so I bought them both. On the way back upstairs to the office, I noticed something strange on the labels. Each had cost $1, but the pack of Peanut Butter M&M's was a very tiny bit lighter: 0.06 ounces lighter!

I wanted to know why, so I called a couple of experts and asked for their theories:

Theory No. 1: Peanut Butter M&M's are more expensive to make.

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Planet Money
5:41 pm
Thu March 6, 2014

Does Raising The Minimum Wage Kill Jobs?

Kenzo Tribouillard AFP/Getty Images

Originally published on Thu March 6, 2014 7:50 pm

President Obama has called for increasing the minimum wage, saying it will help some of the poorest Americans. Opponents argue that a higher minimum wage will lead employers to cut jobs.

Figuring out the effect of raising the minimum wage is tough. Ideally you'd like to compare one universe where the minimum was raised against an alternate universe where it remained fixed.

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Planet Money
3:39 am
Fri January 17, 2014

The Birth Of The Minimum Wage In America

Franklin D. Roosevelt Libarary

Originally published on Fri January 17, 2014 4:46 pm

In 1895, legislators in New York state decided to improve working conditions in what at the time could be a deadly profession: baking bread.

"Bakeries are actually extremely dangerous places to work," says Eric Rauchway, a historian at the University of California, Davis. "Because flour is such a fine particulate, if it gets to hang in the air it can catch fire and the whole room can go up in a sheet of flame."

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Planet Money
3:00 am
Fri November 22, 2013

A Bitcoin Insider On Crime, Congress And Satoshi Nakamoto

This is not a bitcoin.
eagleapex's posterous Flickr

Originally published on Fri November 22, 2013 11:48 am

For more on what Bitcoin is and how it works, see our story "What Is Bitcoin?"

Gavin Andresen is chief scientist at the Bitcoin Foundation. I first talked with him about Bitcoin, the virtual currency, back in 2011. I checked back in with him this week, because so much has been going on with Bitcoin lately.

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Planet Money
3:06 am
Fri November 15, 2013

What's A Bubble?

Robert Shiller and Eugene Fama shared this year's Nobel Memorial Prize.
AP

Originally published on Sun November 17, 2013 1:58 pm

Robert Shiller was surprised when he got the call telling him he'd won the Nobel Memorial Prize in economics — surprised that he'd won (of course), but also surprised that he was sharing the award with Eugene Fama.

"He and I seem to have very different views," Shiller told me. "It's like we're different religions."

In particular, they have very different views about economic bubbles.

"The word 'bubble' drives me nuts, frankly," Fama told me.

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Planet Money
3:29 am
Fri October 25, 2013

What Happens When You Just Give Money To Poor People?

Bernard Omondi got $1,000 from GiveDirectly.
Jacob Goldstein NPR

Originally published on Fri October 25, 2013 10:34 am

For more of our reporting on this story, please see our work in The New York Times Magazine and on This American Life.

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Planet Money
3:26 am
Fri October 18, 2013

I Lent $999.78 To The Federal Government*

NPR

Originally published on Fri October 18, 2013 1:29 pm

Earlier this week, I bought a Treasury bill.

Everybody calls Treasury bills T-bills, and they work like this: The government promises to pay holders of T-bills a specific amount on a specific day in the near future. For the T-bill I bought, the government promised to pay $1,000 on Oct. 31.

I bought the T-bill on Tuesday, before Congress had made the debt-ceiling deal, so it was unclear whether I would get paid back on time.

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Planet Money
3:00 am
Thu October 10, 2013

What A U.S. Default Would Mean For Pensions, China And Social Security

iStockphoto.com

Originally published on Thu October 10, 2013 12:38 pm

What would happen if Congress doesn't raise the debt ceiling and the U.S. defaults on its debt later this month? The broad economic implications are unpredictable, but a default could cause huge trouble for the global economy.

But whatever happens to the global economy, one thing is clear: People all over the world who have loaned the U.S. government money won't get paid on time.

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Planet Money
3:36 am
Mon September 30, 2013

One Key Thing No One Knows About Obamacare

Getty Images

Originally published on Mon September 30, 2013 7:44 am

Tuesday is a big day for Obamacare. The online marketplaces where people can shop for health insurance are supposed to open for business.

No one really knows who is going to sign up — not the Obama administration, not the insurance industry, not the president's critics. Yet the success of the law hangs on this question: Will the right mix of people sign up? In particular, will healthy people buy health insurance?

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Planet Money
3:21 am
Mon September 2, 2013

Ecuador To World: Pay Up To Save The Rainforest. World To Ecuador: Meh.

An aerial view of the Yasuni National Park, in Ecuador's northeastern jungle.
Dolores Ochoa AP

Originally published on Mon September 2, 2013 7:04 pm

The government of Ecuador has abandoned a plan that would have kept part of the Amazonian rainforest off limits to oil drilling. The initiative was an unusual one: Ecuador was promising to keep the oil in the ground, but it wanted to be paid for doing so.

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