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The Power of the Multiplier 17:09 Lena: Miles, we keep coming back to this idea that the government needs to step in when things get shaky. But there’s always that one big counter-argument you hear: "Where is the money going to come from?" and "Does government spending actually work, or is it just throwing money down a black hole?"
17:26 Miles: That brings us to one of the most famous—and debated—concepts in all of economics: the Keynesian Multiplier. It’s a simple but radical idea that John Maynard Keynes popularized during the Great Depression. He argued that if the government spends, say, one hundred million euros on a bridge, that money doesn't just "vanish." It becomes income for the workers and the suppliers. Then *they* spend a portion of that income on groceries, clothes, and rent. That spending becomes income for the baker and the landlord, who then spend *their* portion, and so on.
17:57 Lena: So that original 100 million ripples through the whole economy and ends up creating much more than 100 million in total growth?
0:36 Miles: Exactly! If the "marginal propensity to consume"—the fraction of extra income people actually spend—is high, that multiplier can be huge. For example, if people spend 60 cents of every extra euro they get, a 100 million euro project could theoretically boost the total economy by 250 million euros. It’s the "Keynesian Cross" in action.
18:27 Lena: But wait—if it’s that easy, why don't governments just spend infinite money and make everyone rich? There has to be a catch.
18:34 Miles: Oh, there are several. Classical economists argued for "crowding out"—the idea that if the government borrows money to spend, it drives up interest rates, which makes it harder for private businesses to borrow and invest. So the government spending just "replaces" private spending instead of adding to it. Then there’s "Ricardian Equivalence" again—the idea that people will save their extra income because they expect higher taxes later.
18:58 Lena: Right, the "I’m not falling for this" effect.
12:23 Miles: Precisely. But what’s really exciting in the latest research—like the work by Auclert and his colleagues in 2024—is this idea of "Heterogeneous Marginal Propensities to Consume." It turns out the multiplier isn't a fixed number for the whole economy. It depends entirely on *who* gets the money.
19:18 Lena: Let me guess—giving a hundred euros to someone who is struggling to pay rent has a bigger impact than giving it to a billionaire?
19:26 Miles: You’ve got it. Using microdata from things like lottery winnings, researchers found that lower-income households spend a much larger fraction of any windfall. They have a high MPC. Wealthy households, who already have everything they need, tend to just save it. So, if a government stimulus is targeted at the people who will actually spend it, the multiplier can be significantly greater than one.
19:49 Lena: That feels like a huge "Aha!" moment for policy. It means that "Social Justice" and "Economic Efficiency" might actually be the same thing. If you help the people at the bottom, you’re actually fueling the engine for everyone.
20:03 Miles: It really flips the "trickle-down" theory on its head. It’s more like "bubble-up" economics. This is a core part of the "Pro-employment Macroeconomic Framework" that the ILO—the International Labour Organization—is pushing for. They argue that we should judge economic policy not just by the GDP number, but by whether it creates "decent work" and living wages. Because when workers have secure, well-paying jobs, they spend more, which creates more demand, which creates more jobs. It’s a virtuous cycle.
20:31 Lena: But the New Consensus we talked about earlier doesn't really focus on that, does it? It’s more about the "thermostat" of interest rates.
20:39 Miles: Right, and the ILO is calling for "Policy Coherence." They’re saying you can’t have the Ministry of Labour trying to create jobs while the Central Bank is jacking up interest rates to slow things down and the Ministry of Finance is cutting spending to lower the deficit. If they aren't pulling in the same direction, they just cancel each other out and leave the workers in the lurch.
21:00 Lena: It’s like a rowing team where everyone is rowing at a different speed and in a different direction. You just spin in circles while everyone gets exhausted.
21:10 Miles: And that exhaustion is what leads to "jobless growth" or "precarious work," where the economy looks good on paper, but people feel like they’re drowning. The goal for 2026 is to bring the "multiplier" back to the center of the conversation—recognizing that strategic, targeted government investment in things like the green economy or education isn't just a "cost," it’s a way to unlock the potential of the whole system.