How the Phillips Curve shaped macroeconomics : Planet Money When economists and policymakers talk about getting inflation under control, there's an assumption they often make: bringing inflation down will probably result in some degree of layoffs and job loss. But that is not the way things have played out since inflation spiked last year. Instead, so far, inflation has come down, and unemployment has stayed low.

So where does the idea of this tradeoff – between inflation and unemployment – come from?

That story starts in the 1940s, with a soft-spoken electrical engineer-turned-crocodile hunter-turned-economist named Bill Phillips. Phillips was consumed by the notion that there are underlying forces at work in the economy. He thought that if macroeconomists could only understand how those forces work, they could keep the economy stable.

On today's show, how the Phillips Curve was born, why it went mainstream, and why universal truths remain elusive in macroeconomics.

This episode was hosted by Willa Rubin and Nick Fountain, and produced by Sam Yellowhorse Kesler. It was edited by Molly Messick, and engineered by Maggie Luthar. Sierra Juarez checked the facts.

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How the Phillips Curve shaped macroeconomics

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There's this thing that has kind of been a mystery to me. Why, when inflation really set in recently - why did so many of us assume that, to get it under control, there would have to be massive layoffs and unemployment? We now know that isn't true. We didn't need tons of people to lose their jobs to get inflation down. So why were so many of us convinced? That idea, turns out, comes from somewhere - one person who changed how economists and central bankers think about inflation and how to fight it. I heard his story from none other than PLANET MONEY producer Willa Rubin. Hi, Willa.


Hi, Nick Fountain.

FOUNTAIN: All right. Where should we start?

RUBIN: We should start with his name.

FOUNTAIN: (Laughter) Good call.

RUBIN: Bill Phillips had a very adventurous life. He was born in New Zealand in 1914. He was an electrical engineer. He worked at a gold mine. At one point, he was a crocodile hunter.

RICHARD LIPSEY: He was fairly short. He was a chain smoker. He had a strong New Zealand accent.

RUBIN: This is Richard Lipsey. He was a colleague of Bill Phillips way back when. They were friends. And he told us a story about how Bill Phillips became an economist that I love because it captures just how young and weird economics was back in the 1940s, when Bill Phillips started off.

FOUNTAIN: Bill Phillips landed at the London School of Economics after World War II. He didn't have much formal economics training, but he gets consumed by an idea that there are underlying forces at work in the economy, and if you could just understand how those forces work, you could keep the economy stable.

RUBIN: Right. But Bill Phillips' friend, Richard Lipsey, says he had a pretty unconventional way of trying to study things.

LIPSEY: He was a bit of a tinker. He was a very handy man.

FOUNTAIN: Remember; he was an engineer. And so when Phillips was first trying to understand how the economy worked, he was the type of person - you probably know one - who had to go and build a thing.

LIPSEY: He went home, and in his garage, he built the famous machine which was a water flow model of how the economy behaved.

RUBIN: A water flow model. This machine is a real thing. You can see one at the Science Museum in London today. It's this giant, fridge-sized contraption with compartments and pipes and levers each representing a different part of the economy.

LIPSEY: So you had a series of tanks and flows between them, and you had consumers and investors and governments. And to see it, you know, when you're used to just reading it was really quite spectacular.

RUBIN: Lipsey remembers standing next to the machine and pulling levers that controlled different parts of the economy - monetary policy or fiscal policy. And he remembers water sloshing around from tank to tank.

FOUNTAIN: Did you ever have to use the mop and a bucket? Or would - was there a janitor there to clean up afterwards?

LIPSEY: No, it didn't leak much. It was an engineering feat. And by and large, it worked pretty well. And you realize that controlling the economy was far more complicated than the textbooks told you.

FOUNTAIN: But people weren't sold on Bill Phillips' machine when he first rolled it into the prestigious London School of Economics for its debut. Phillips was a nobody, not a real economist. So people showed up to see this thing he'd made but not for the right reasons.

LIPSEY: All the staff - the junior staff came out to humiliate this upstart idiot. And it turned out after 10 minutes that he knew more than everybody there, and they shut up. And on the strength of this, he was offered a job at the London School of Economics.

RUBIN: So that's the story of how Bill Phillips got established as an economist. But the reason we're talking about him today is that Phillips' next insight would shape how we understand one of the most fundamental relationships in the economy. Hello, and welcome to PLANET MONEY. I'm Willa Rubin.

FOUNTAIN: And I'm Nick Fountain. Pretty much as long as economists have been around, they've had this dream that their field could be a science, that their work was to find universal truths that govern the economy and then use those truths to help keep things stable, help make people's lives better.

RUBIN: Bill Phillips applied that scientific approach to two of the most important measures of the economy - unemployment and inflation. He saw that there was a trade-off between the two, one that maybe you could exploit, just like levers on a machine.

FOUNTAIN: Today on the show, how a croc hunter-turned-economist changed the world.

RUBIN: Of macroeconomics.

FOUNTAIN: He changed the world. I'm saying it.


FOUNTAIN: Where we last left Bill Phillips, he'd made his water flow machine that modeled the economy, and he'd gotten his gig at the London School of Economics.

RUBIN: Yeah, and let's set the scene a little. It's the early 1950s. Macroeconomics is young. It was invented 15 or so years before by John Maynard Keynes. And so it's a heady time for the field. There's a lot of debating, also a lot of cigarettes.

LIPSEY: The common room was a cloud of smoke, and we'd have a glass of sherry or two. If it was me, it would be two.


RUBIN: And the thing that Bill Phillips was constantly talking about in the common room was that obsession that got him into economics in the first place - how to avoid the huge swings of living in a market economy.

FOUNTAIN: So Phillips starts looking at these two things that can really throw off an economy - inflation and unemployment. He knows intuitively that there's a connection between the two. Everyone at the time sort of got this. When unemployment is low, people have bargaining power. It's easier for them to ask for raises. And those raises - you know, wage growth - make prices go up.

RUBIN: But just how to turn that observation about unemployment and inflation into something really concrete, a tool for guiding the economy - that was the real question.

FOUNTAIN: So one day - a Friday, the legend goes - Phillips is talking about his quest, and a fellow professor says, hey; I think I know the exact dataset that'll help you crack open the case. It's about a hundred years of collected wage and unemployment data all from the United Kingdom. Phillips gets his hands on the data set and then pulls a classic Phillips. He goes home and makes something.

LIPSEY: He went home on Friday, and he came back on Monday morning. Everybody said, wow.

FOUNTAIN: Yeah, 'cause what he'd found was a clear tie between unemployment and inflation - that in times when most people have jobs, aka when unemployment is low, inflation tended to be high. And the opposite was true, too. When a lot of people were out of work, inflation tended to be low.

RUBIN: You can see it in the graph that Phillips had drafted over that weekend. On one axis is the unemployment rate, and on the other was the growth rate of wages, which, at the time, was a major cause of inflation. On his graph, Phillips drew a line - kind of more like a curve - roughly following those data points.

LIPSEY: They came back with this drawing, and here it is. Here's the curve. And...

FOUNTAIN: And we're still talking about it today.

LIPSEY: Yeah. Yeah.

RUBIN: Over the next few years, his idea starts to catch on. Lipsey works with Phillips, writes a follow-up paper that backs up the original finding. Other economists start testing it out with data from different countries. One of them, Paul Samuelson, says it largely checks out for American data. He gives this thing a name, the Phillips Curve. And then in 1961, Samuelson puts the Phillips Curve in his textbook, which is, like, the textbook that generations of economists get trained on.

FOUNTAIN: So the curve is gaining in popularity. But weirdly, Phillips kind of exits the scene not long after this. He moves to Australia, doesn't think about the curve much anymore. But it doesn't matter. By this point, the Phillips Curve is bigger than him.

RUBIN: Because the Phillips Curve made a lot of economists think maybe they'd done it - unlocked a stable law of economics. You could pick a point on the curve and aim for it. It was a kind of recipe for economists to use.

FOUNTAIN: Yeah. At this moment in history, there's this new faith that economists can shape people's lives for the better in really tangible ways. In the White House, economists are describing this trade-off between unemployment and inflation in briefings with JFK and LBJ. The Phillips Curve had gone mainstream.

RUBIN: When you hear Lipsey talk about these times, it kind of sounds like some of the best times of his life. It's the '60s. World War II is a fading memory. There's a sense of optimism, freedom.

LIPSEY: That was a great time in England - you know, Carnaby Street and The Beatles...


THE BEATLES: (Singing) Love, love me do.

LIPSEY: ...Kingston Trio, The Limeliters, Peter, Paul and Mary.


PETER, PAUL AND MARY: (Singing) If had a hammer, I'd hammer in the morning. I'd hammer in the evening...

LIPSEY: And that was a wonderful time.

FOUNTAIN: In 1967, Lipsey got on a plane to the U.S. He was going to attend the yearly American Economics Association conference. And he was going to fly first class, which sounds like it was amazing.

LIPSEY: The head waiter would come. We'd start with vodka and Russian caviar. Then you'd have hors d'oeuvres by the thousands.


RUBIN: Wow (laughter).

LIPSEY: And every time, you had French wines of all sort. You had main course, and they had roast beef on a trolley and then dessert and then fruit, liqueurs of every sort. So talk about having too much to drink on a trip.

RUBIN: What Lipsey didn't know yet was that at this conference, the Phillips Curve would enter a whole new era because Milton Friedman, the most famous economist of his time, was about to give a speech. It happened on the final night. Friedman walks up on stage.

FOUNTAIN: What did he look like?

LIPSEY: Little man. I mean, in stature (laughter), not in - I can't tell you anything more.

FOUNTAIN: Up on stage, Friedman more or less says, sure, you found something interesting there. But the idea that the Phillips Curve precisely maps out a stable relationship between unemployment and inflation, one that will hold up in the long-term? No way.

RUBIN: For example, he says the Phillips Curve doesn't really account for what's called inflation expectations. This is the idea that once people experience high inflation, they start to expect it and then they change their behavior.

What were you feeling when you were watching him do these critiques?

LIPSEY: I thought it was quite interesting.

RUBIN: You weren't (laughter) - you weren't annoyed? He was poking holes in your work.

LIPSEY: I can't speak for my emotions at that time. But I certainly took on board the expectations thing.

FOUNTAIN: Friedman had said that the Phillips Curve as it stood was too simplistic. And that amounted to a warning to all of the economists who were counting on it that at the very moment they needed the Phillips Curve to help them guide the economy the most, it would break down.

RUBIN: Alan Blinder, another famous economist we talked to, was a grad student when Friedman made his big speech.

FOUNTAIN: So this '67 speech, it kind of sent shockwaves across the world, right?

ALAN BLINDER: Yeah. Well, I mean, you exaggerate a little. Most of the world pays no attention to anything...


BLINDER: ...That happens in economics.

FOUNTAIN: Blinder is a straight talker, and he says that Friedman's warning didn't take long to come true because after those loose, riding-high moments of the '60s, the '70s was kind of a rude awakening. You can hear it in the music of the day.

RUBIN: Shoutout to my favorite band, The Clash, literally singing about unemployment.


THE CLASH: (Singing) Career opportunities, the ones that never knock. Every job they offer you is to keep you out the dock. Career opportunity, the ones that never knock.

FOUNTAIN: Blinder was in the U.S., far away from any British punks, but he still remembers the supply shocks that made him sit in long lines at the gas stations in the '70s. He remembers the high inflation. He remembers the unemployment spiking. This combination was so bad it got its own name.

BLINDER: It got the name stagflation. Both are moving in the wrong way. We don't want inflation up. We don't want unemployment up.

FOUNTAIN: What does stagflation feel like for someone who's never lived through it like me?

BLINDER: Well, it felt lousy.

RUBIN: It felt lousy. And also, according to the Phillips Curve, stagflation was not supposed to happen. When either unemployment or inflation went up, the other was supposed to go down. Friedman had absolutely been proven right.

FOUNTAIN: And that meant economists needed to go back to the drawing board and keep up their search for that fundamental truth. Keep looking for that roadmap that would help them guide the economy. That's coming up after the break.


FOUNTAIN: Hey, it's Nick Fountain. Call it affirmative action for rich kids, America's elite colleges give them a huge admissions advantage over middle-class kids with the same SAT scores. And it's more than just legacy admissions.

RAJ CHETTY: It turns out, maybe contrary to what a lot of people would think, athletes recruited at these colleges tend to come from much higher-income families, not lower-income families. And that contributes to this.

FOUNTAIN: We hear from one of the authors of that latest research, a PLANET MONEY favorite, Raj Chetty, on our latest bonus episode for PLANET MONEY+ listeners. If that's you, thank you for your support. And if it's not, it could be. Sign up at Thanks.


RUBIN: If macroeconomics was in its adolescence when Phillips first drew his curve, this next part of the story is a coming-of-age moment, because that simple observation about how inflation and unemployment are linked, it needed to grow up.

FOUNTAIN: This is a thing that happens pretty often in science. It's healthy, actually. People think they have a good picture of what's going on, and then someone comes along and says, actually, it's way more interesting and complicated than you thought. Like atoms, you know, the smallest things that are out there, it turns out those are made of protons and neutrons and electrons. Would you look at that?

RUBIN: Yeah. That's kind of what happens with the Phillips Curve. After Friedman's critique and the mess of the 1970s, economists are rebuilding the curve. They take this relatively simple relationship - unemployment, inflation - and turn it into a more complex equation.

FOUNTAIN: So those inflation expectations - economists make sure those are in there, also the supply shocks that they just learned about and also what's called the natural rate of unemployment. Basically, everything they knew that influenced how inflation and unemployment played out got added. And this is how we got to a new and improved Phillips Curve, the Phillips Curve 2.0.

RUBIN: And the reason we called Alan Blinder is that he got to use this Phillips Curve 2.0 at an important moment for the U.S. economy - 1994, when he gets the job of vice chair of the Federal Reserve - second in command.

FOUNTAIN: Best job of your life?

BLINDER: Yeah, probably. Probably.

FOUNTAIN: It's cool to be able to pick up the phone and people do what you want. That's...

BLINDER: Yeah. They mostly did. Although, as in many bureaucracies, they didn't always do what you want.


BLINDER: They always said they would do what you want.

RUBIN: Sure.

BLINDER: And sometimes a week later you'd say, wait, they didn't do that, and you had to call them again.

FOUNTAIN: Blinder gets the job at a tricky time to be a central banker. It looked like inflation was going to start going up, which is scary if you're a Fed official. You don't want to be the vice chair who lets inflation rears its ugly head on your watch.

RUBIN: So Blinder shows up for his new job, and the pressure is on.

BLINDER: One of the first things I did was asked for a briefing from staff - and they are good at this - on the Phillips Curve.

FOUNTAIN: And when the vice chair asks, 20 research economists spend the weekend trying to figure out...

BLINDER: Yeah, yeah, yeah. And if it was the chairman who asked, it would have been 50 research economists. Yeah.


FOUNTAIN: Was this literally one of the first things you did when you got there?

BLINDER: Oh, yeah. Yeah - might have been the first.

FOUNTAIN: 'Cause this is one of the most pressing questions of the age.

BLINDER: It was. It was. The Fed had, just before I joined, started raising interest rates to fight inflation. So question number 1, 2, 3, 4, and 5 was all about how far would the Fed have to go to prevent inflation from going up?

RUBIN: How far would the Fed have to raise interest rates to cool the economy? What Blinder gets back from his researchers is a bunch of different scenarios - not just one Phillips Curve, but a whole stack of them showing all these possible outcomes for the economy based on different economic measures. And from what Blinder could see, these forecasts pointed to inflation trending up. So he makes his call.

FOUNTAIN: So did you vote to hike rates?


FOUNTAIN: And when you did that, essentially what you were doing was...


FOUNTAIN: ...Making a choice on the Phillips Curve. You were saying, we want to increase unemployment just slightly...

BLINDER: Just slightly.

FOUNTAIN: ...Cause a little bit of pain - but not tremendous pain - so that we can keep inflation good.

BLINDER: Correct.

RUBIN: Blinder wanted to walk a fine line - stamp out inflation without causing a recession - what we're calling a soft landing these days.

FOUNTAIN: Right. So Blinder and his team, they continued to consult their new Phillips Curve forecasts, and they continued to hike rates for about a year.

BLINDER: And that was just right. We did get the soft landing. And you asked about the nicest job. It's really nice to have praise gushing in all over the place for the soft landing that the Fed had miraculously achieved.

RUBIN: It was sort of like Blinder and his colleagues had delivered on the original promise of the Phillips Curve. They'd used it to keep inflation down, keep the economy stable.

BLINDER: It was the best 'cause, you know, the view in the markets. We were a bunch of geniuses and did it exactly right.

FOUNTAIN: Blinder left the Fed in 1996 fully believing in the Phillips Curve or the Phillips Curve 2.0. For him, it was a road map. With it, he could navigate the graphs of unemployment and inflation and figure out a way forward.

RUBIN: The fundamental idea of the Phillips Curve - that in order to get inflation down, you needed people to lose their jobs - that had become gospel. But if you ask Blinder now...

Are you a true believer in the Phillips Curve?

BLINDER: No. I'm no longer a devotee of the Phillips Curve. I've seen the error of my ways.

RUBIN: What happened that made him stop believing in the Phillips Curve? Well, after Blinder got his perfect soft landing, inflation more or less stayed still for decades from the late '90s until just a couple years ago.

FOUNTAIN: And this was a time when so many things were happening in the economy. There was a tech boom. There was a tech bust. There was the Great Recession. Unemployment took some wild swings, but inflation didn't really budge, which is not what the Phillips Curve - even the Phillips Curve 2.0 - said should happen. All this was very disconcerting to Blinder.

BLINDER: If you don't understand what's driving inflation up or down, you've lost an important tool, and you're wandering a little bit in the forest when it comes to predicting inflation.

FOUNTAIN: You've lost maybe the most important tool that monetary policy makers have, right?

BLINDER: I think, you know, not everybody would say that, but I would say that.

FOUNTAIN: That's terrifying. That means that we can't control...

BLINDER: Yeah. It's terrifying. The reason it wasn't terrifying was until around 2022, inflation just wasn't the problem. So the reason it's terrifying is that if you lose your Phillips Curve, you don't quite know what to do if you need to bring inflation down.

FOUNTAIN: Which, of course, we need to do now. It's the Fed's main focus today.

RUBIN: And it's not like economists have entirely given up on the Phillips Curve and its way of understanding the economy. It's more like the Phillips Curve needs another round of rethinking. Back when Bill Phillips first came up with his curve, it was a comforting idea. Maybe there could be laws of economics just like there are laws of physics.

FOUNTAIN: Right. And it's natural to see something happen over and over again in the world and think it's some sort of law, some sort of universal truth that you can lean on. But the story of the Phillips Curve shows that that is really hard to do in economics. Economists can make observations and use them as guides. They can even update those observations over time. But economies aren't static. They're complex. They're made up of people who respond to the economy and change it in the process.

RUBIN: Which means that economists might never get to universal truths. They'll always be learning as history unfolds. They'll always be playing catch-up.


RUBIN: This episode was produced by Sam Yellowhorse Kesler. It was edited by Molly Messick and engineered by Maggie Luthar. Sierra Juarez checked the facts.

FOUNTAIN: Many, many thanks to Ann Owen and Ricardo Reis (ph) for talking to us for a long, long time about Bill Phillips' work and helping us understand it. I'm Nick Fountain.

RUBIN: And I'm Willa Rubin. This is NPR. Thanks for listening.


FOUNTAIN: Professor Blinder, do you know who Christopher Walken is?

BLINDER: Give me a hint. That rings a vague bell.

FOUNTAIN: Famous actor. He was in, like, "Batman..."

BLINDER: Oh, yeah, yeah, yeah.

FOUNTAIN: We were telling people around the office that we were interviewing you, and they were like, we think Mr. Blinder is the Christopher Walken of economics. I don't know what you feel about that.

BLINDER: I don't know if that's a compliment or an insult.

FOUNTAIN: It's absolutely a compliment (laughter).

BLINDER: OK. I'll take it then.

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