Planet Money

The Church of Jesus Christ of Latter-day Saints teaches that each Mormon in good standing should tithe 10 percent of his or her income."That's written in stone, and preached from the pulpit," says Gordon Dahl, an economist at the University of California, San Diego, who is Mormon.But while the church is very precise about that figure — 10 percent of income — it does not tell its members what income means."Which is really interesting to us economists, because we want to know how people define income," says Dahl.As anyone who has ever done their taxes knows, figuring out what counts as income is harder than it sounds.On the show today, we look into how Mormons figure out how much to tithe, and what that tells us about how people think about income and taxes.

Today on the show, we visit a giant pool of money — worth trillions of U.S. dollars! — at the People's Bank of China, the country's central bank.To understand how the money got there, we talk to Jacky Jiang and Rosalia Yang, a pair of very friendly exporters who show us around a factory where they make fake-wood flooring.They tell us about the changes China is going through, and explain why that pool of money might soon start flowing back to the U.S.

Today, in the second of our two-part series on private equity, we take another look at Bain Capital — the firm co-founded by Mitt Romney.Last Tuesday, in the first part of the series, we looked at a deal Bain did during Romney's tenure that went bad. Today, we tell the story of a deal that turned out better.And we dig into the arguments about private equity's broad role in the economy.

"History is a battle between creditors and debtors," Philip Coggan says on today's show. "Every so often these two clash, there is a crisis and the whole system is remade."Coggan, who writes the Buttonwood column for the Economist, is author of the book Paper Promises: Debt, Money, and the New World Order."We had a crisis in the 1930s, in the 1970s and we've got another one now."We're not even close to resolving the latest crisis, according to Coggan. The debate over debt is "what politics and economics are going to be about for the next 10 years," he says.

Are private-equity firms job-destroying monsters? Or are they knights in shining armor, riding in to fix troubled companies and make the economy work better?When you have a presidential candidate who used to run a private-equity firm, the arguments tend to shed more heat than light.So we decided to look at what private equity firms actually do — by telling the stories of two companies purchased by Bain Capital, the private equity firm co-founded by Mitt Romney.On today's show, we look at a deal gone bad. On a future podcast, we'll look at another deal that turned out differently.Romney's campaign wouldn't comment on tape for the podcast, but they did send us this statement:"Mitt Romney spent 25 years as a businessman and entrepreneur. ... At Bain Capital, he helped launch and guide a private equity and financial services firm. Bain Capital invested in many businesses; while not every business was successful, the firm had an excellent overall track record and created jobs with well-known companies like Staples, Dominos, and Sports Authority."

When you walk around a big city in China, it feels like an entrepreneurial free-for-all — guys selling stuff on street corners, lots of little shops, everybody hustling.But when you pull back the curtain on the country's economy, you find the government everywhere. The government owns, among other things, the country's biggest cell phone carrier, the three biggest airlines and the four biggest banks.Those state-owned banks in particular play a central role in the country's economy.Chinese people have one of the highest savings rates in the world, and they don't have many options for investing the money they save. So they put lots of their money in ordinary savings accounts at those state-owned banks.The banks, in turn, lend a lot of that money out to other government-owned companies, typically at very low interest rates. Those companies go out and build lots of new stuff. All that building contributes a huge chunk of China's growth.But the building can't go on forever. In fact, China may already have built too much stuff with borrowed money.

What should the government pay for?On today's Planet Money, we pose that question to Charlie Wheelan, author of the book Naked Economics, and one-time Congressional candidate. (He lost).He gives us the econ 101 answer: The government should definitely pay for something if it's a public good, which Charlie defines as "something that we all need that will make our lives better, but the market will not and cannot provide."The textbook example is a lighthouse. Other examples of public goods include national defense and autopsies. Everyone benefits from the medical knowledge autopsies provide, but it's not really in any individual's interest to pay for an autopsy.Somehow, this fact leads us to call 1-800-AUTOPSY.Note: Today's podcast originally aired in 2010.

On today's show: Four genius ideas.These ideas, as it happens, have all appeared in Planet Money radio stories. But they've never been on the podcast. A Man. A Van. A Surprising Business Plan. Rethinking The Oreo For Chinese Consumers What Do The Dow's Daily Swings Mean? Not Much. How A Computer Scientist Tried To Save Greece

Can we have a banking system that provides good services to people at reasonable rates? A banking system that doesn't bring down the global economy every few decades?Anat Admati thinks we can. She's a finance professor at Stanford, but she never paid much attention to banks until the financial crisis. (This is not unusual in the superspecialized world of academia.)After the crisis hit, Admati started reading up on banks. And, in a basic banking textbook, she came upon a single line that changed her career."I sat in my office and I thought, 'Something is really wrong in banking.' "On today's show, Admati tells us what she thinks is wrong in banking — and how she thinks we can fix it.

This is what it's like to host the Super Bowl: For one weekend, your city is the focus of the sporting universe. Fans flock in droves. They eat at your restaurants and sleep in your hotels. They buy the "I ♥ [your city]" t-shirts.  The NFL estimates that hosting the country's premier sporting event will give the local economy a $300-400 million jolt. Economist Victor Matheson doesn't buy it.. In today's podcast, Matheson, a professor at the College of Holy Cross, presents the case against hosting the Super Bowl.

On today's show, we hear how a hobby turns into a lucrative one-man business — and how Apple's App Store is transforming the Internet economy.The gist is super simple. In fact, it's something that's been going on in the physical world for thousands of years: Giving people a convenient way to buy cheap products.Our guest on the show is Marco Arment, one of the founders of the blogging platform Tumblr. A few years back, Marco launched a little side project called Instapaper.

On the podcast today, we get a glimpse from inside the room where money changes hands. Jimmy Williams used to lobby for the powerful National Association of Realtors.Williams tells us about some of the ridiculous issues he's lobbied for, the steady flow of money that congresspeople need, and how he wants to take down the crazy campaign finance system.

It's the 11th hour for Europe's debt crisis. Again.Greece still can't pay back all the money it owes. So it's trying to cut a deal with its creditors. (Again.)We've been wondering for years: Who are the people who loaned money to Greece? Are they suckers? Brilliant investors?On today's podcast we find someone who loaned Greece money: Hans Humes. He runs a hedge fund called Greylock Capital Management. Turns out, his office is just a few blocks away from ours.Humes is one of the guys trying to hammer out a deal with Greece. He explains just how complicated the negotiations are — and how, even among people who loaned Greece money, there are huge divisions.

Katy Perry killed it on the pop charts last year. She went No.1 five times. She was the most played artist on the radio. But the record industry is so weird, it's hard to know whether this kind of success translates into huge amounts of money for her label.How much did the label spend on Katy Perry? And how much did they make?On today's show, we try to figure it out.

It seems like there's always some country or another that the United States is imposing sanctions on. The reasons change, but the idea is always the same: economic coercion.This month, it's Iran. In response to Iran's alleged pursuit of nuclear weapons, President Obama signed a law that punishes banks for doing business with Iran's central bank. This makes it difficult, in theory, for Iran to sell its oil around the world.You can see why sanctions are so appealing for the U.S. government: Rather than go to war to stop Iran's nuclear program — to risk American lives — the U.S. can block money from going in and out of the country. That makes life miserable for the Iranians and, in theory, persuades them to give up their nuclear ambitions.But do sanctions work? Have sanctions ever really worked? Today, we talk to Gary Hufbauer, author of the book Economic Sanctions Reconsidered. And we hear a first-hand account of what life in Iraq was like under the sanctions of the 1990s.