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Welcome to the Deep Dive.
We're here to help you get right to the core of key ideas.
And today we're tackling something that, well, touches everyone.
Taxes.
Absolutely.
It's a going way back.
The American Revolution in 1776 was partly sparked by anger over taxes.
Right.
And modern politics is still full of arguments about the best way to tax people.
There's that famous quote from Oliver Wendell Holmes, Jr.
Taxes are what we pay for civilized society.
A necessary cost for sure.
But while we need them, our mission today is to really dig into the full economic cost.
Just how high is that price for civilization?
And we're basing this on a chapter from a leading microeconomics textbook.
So building on what we've discussed before.
Exactly.
Last time we looked at how a tax hits prices and quantities and who bears the burden.
Buyers versus sellers, yeah.
Today we're going deeper.
We'll use welfare economics to measure the impact on actual economic well -being, the welfare of everyone in the market.
And the key idea is?
The key insight is that the cost of taxes to buyers and sellers is often actually bigger than the money the government collects.
There's this hidden cost.
OK, let's unpack that.
You mentioned before it doesn't really matter who the tax is officially levied on, buyer or seller.
That's right.
The market outcome, the final price and quantity ends up being the same either way.
But the tax does create something you call the tax wedge.
Yes, exactly.
A wedge.
Think of it as driving a gap between the price buyers pay and the price sellers receive.
So normally there's one price with a tax.
With a tax, the price buyers pay goes up and the price sellers keep goes down.
That difference, that gap is the tax.
And the crucial effect of that wedge.
It means fewer goods get bought and sold.
The quantity falls compared to a market without the tax.
The market literally shrinks.
Fewer transactions.
OK.
So to measure the impact of the shrinking, we need those welfare economics tools you mentioned.
Right.
We look at consumer surpluses.
That's the benefit buyers get measured as what they're willing to pay minus what they actually pay.
And for sellers?
For sellers, it's producer surplus.
That's the price they receive minus their cost of making the good.
Makes sense.
But the tax adds another piece to the puzzle.
It does.
The government collects tax revenue.
You calculate it simply by multiplying the size of the tax, let's call it t, by the quantity of goods sold, q.
So t times q.
And that revenue isn't lost, right?
It pays for things.
Correct.
That revenue funds public services, roads, schools, police, helping the needy.
It provides a benefit to society just indirectly through government spending.
OK.
So let's compare.
What does total welfare look like without a tax?
Without a tax, the market finds its equilibrium.
Price P1, quantity Q1.
Consumer surplus is the area under the demand curve and above the price.
Let's call that areas A plus B plus C on a standard graph.
And producer surplus?
That's the area above the supply curve and below the price.
We can call that D plus E plus F.
So total surplus is just adding those together.
A plus B plus C plus E plus F.
Exactly.
That whole area between the supply and demand curves up to the equilibrium quantity.
And of course, tax revenue is zero.
Now bring in the tax.
What changes?
OK.
The price buyers pay, PB, goes up.
The price sellers receive, PS, goes down.
And crucially, the quantity sold drops to Q2.
So those surplus areas must shrink.
They do.
Consumer surplus shrinks way down.
Maybe just area A.
Producer surplus also shrinks.
Maybe just area F.
But the government gets something now.
Yes.
The government collects the tax revenue, which on that graph corresponds to the areas B plus D.
It's a rectangle.
Height is the tax, PB minus PS.
Width is the quantity Q2.
So the new total surplus is consumer surplus A plus producer surplus F plus the government's revenue B plus D.
Correct.
Total welfare with the tax is A plus B plus D plus F.
OK.
Let's put those side by side.
What's the net change?
Well, consumers lose B plus C.
Producers lose D plus E.
The government gains B plus D.
Wait, consumers and producers together lose B plus C plus D plus E, but the government only gains B plus D.
What happened to C and E?
That's the crucial point.
Areas C and E just vanish.
They represent the loss in total surplus.
And that is the deadweight loss.
Exactly.
Deadweight loss is that fall in total surplus areas, C plus E in this example, resulting from the market distortion caused by the tax.
It's welfare lost by buyers and sellers that isn't captured as government revenue.
Why does it happen?
Just because the market shrinks?
It's because the tax distorts incentives.
Buyers decide to consume less.
Sellers decide to produce less precisely because the tax makes some trades no longer worthwhile.
The market ends up smaller than the efficient size.
And that inefficiency is the deadweight loss.
Can we make this more concrete maybe with an example?
Sure.
Let's use the books example.
Malik and May.
Malik cleans May's house for $100.
Okay.
Malik's cost, like his time and supplies, is $80.
So he gets $20 of producer surplus.
And May.
May values a clean house at $120.
So she pays $100 and gets $20 of consumer surplus.
So total gain from this cleaning arrangement is $40.
Both are better off.
Win -win.
A mutually beneficial trade, yes.
Now here's where it gets really interesting.
Let's say the government imposes a $50 tax on cleaning services.
Right.
Now can they still make a deal?
Let's see.
May won't pay more than her $120 value.
Okay.
If she pays $120, Malik gets that $120 but then has to pay the $50 tax.
He only keeps $70.
But his cost is $80.
He'd lose $10.
So that doesn't work for Malik.
What if they try starting from Malik's cost?
He needs at least $80 plus the $50 tax.
So he'd need to charge May $130 just to break even.
But May only values it at $120.
She's not going to pay $130.
Exactly.
There's no price between $80,
Malik's minimum after -tax receipt, and $120, May's maximum willingness to pay that can cover the $50 tax.
So the transaction just doesn't happen.
It doesn't happen.
They cancel the cleaning arrangement.
And the result, Malik loses his $20 surplus.
May loses her $20 surplus.
That's $40 of value gone.
And notice the government collects zero tax revenue because the trade didn't occur.
That $40 is pure deadweight loss.
Wow.
So the tax prevented a trade that would have made both people better off.
Precisely.
That's the ultimate source of deadweight loss.
Taxes eliminate some mutually advantageous trades.
On the graph, that deadweight loss triangle, C plus E, represents exactly these loss games.
Between the new quantity Q2 and the potential sellers.
But the tax makes those trades impossible.
Okay.
That makes the cost much clearer.
If these deadweight losses are inevitable, what makes them bigger or smaller?
It really boils down to the price elasticities of supply and demand.
Elasticity.
That's how much quantity changes when price changes, right?
Exactly.
How responsive buyers and sellers are to price signals.
So if people don't change their behavior much when the price moves, the deadweight loss is small.
That's the idea.
Let's visualize it.
Imagine supply is very inelastic.
Think of something where it's hard to change production quickly, maybe beachfront property.
The supply curve is steep.
Okay.
If you put a tax on that, the quantity of supply doesn't fall very much because sellers can't easily reduce supply.
So the deadweight loss triangle is small.
But if supply is very elastic, maybe something easy to make more or less of, like pencils, the supply curve is flatter.
Right.
A flatter, more elastic supply curve means sellers react a lot to price changes.
A tax causes them to cut back production significantly.
The quantity drop is large and the deadweight loss triangle is much bigger.
And does the same logic apply to the demand side?
Inelastic demand means small deadweight loss.
Elastic demand means large deadweight loss.
Precisely.
If demand is inelastic, steep curve, maybe for gasoline,
people need to drive tax.
Hacks won't change consumption much.
Small deadweight loss.
But if demand is elastic, flat curve, like for a specific brand of soda with many substitutes, a tax makes buyers switch easily.
Quantity drops a lot.
The deadweight loss is large.
So the clear lesson is the greater the elasticities of supply and demand, the larger the deadweight loss of a tax.
More responsiveness means more distortion.
You know, what's fascinating here is how this connects to a huge political debate.
The size of government.
Absolutely.
This isn't just theory.
It's central to arguments about government spending and taxation.
Well, if you believe taxes cause large deadweight losses, that's a strong economic argument for a smaller government that interferes less with markets.
Less taxation, less distortion.
Conversely, if you think deadweight losses are generally small, then government programs funded by taxes seem less costly in terms of lost economic efficiency.
Right.
It makes government action seem less economically damaging.
So which is it in the real world?
Especially for the biggest tax, most people face the labor tax.
Ah, the labor tax.
That includes income tax, Social Security, Medicare,
all deductions from paychecks.
It drives a wedge between what your employer pays and what you actually take home.
And the marginal rate, the tax on the last dollar earned can be pretty high, around 40 % for many.
Easily.
And the big disagreement among economists is about the elasticity of labor supply.
How much do people change their working hours or effort when that take -home changes due to taxes?
So one view is that people don't change much.
They work full -time anyway.
That's the argument for inelastic labor supply.
People like prime -age workers, main breadwinners, maybe they have fixed hours or need the income regardless.
If supply is inelastic, the deadweight loss from labor taxes is small.
But the other side argues that labor supply is elastic, at least for some groups.
Yes, they point to several areas where people clearly do respond to wage incentives.
Like what?
Well, think about workers deciding whether to take on overtime hours or second earners in a family, often women,
weighing market work against staying home, especially considering child care costs.
That makes sense.
Their decision might hinge on that after -tax wage.
Exactly.
Also, older workers deciding when to retire or whether to work part -time.
And then there's the underground economy, people working cash -in -hand jobs or engaging in illegal activities, partly to avoid taxes.
So if these groups are quite responsive, then labor supply is more elastic and labor taxes create a larger deadweight loss.
That's the argument.
And this economic debate directly fuels the political arguments about how much we should tax and how big the government should be.
It really highlights how taxes impact behavior, not just wallets.
Okay, let's shift perspective slightly.
What happens as the size of a tax changes?
Say we double a tax.
Does the deadweight loss just double?
Ah, no, it's actually much more dramatic.
Deadweight loss increases more rapidly than the tax size.
More rapidly?
How?
Because the deadweight loss is the area of a triangle on the graph.
The base and height of that triangle are both related to the tax size.
So if you double the tax, you roughly double both the base and height, meaning the area of the deadweight loss increases by about four times.
Four times.
Wow.
So triple the tax and it's nine times the deadweight loss.
Roughly, yes.
It grows exponentially with the tax rate.
A small tax might have a tiny deadweight loss, but a large tax can have a truly enormous one.
Okay, deadweight loss balloons.
What about the tax revenue the government collects?
Does that just keep going up as the tax gets bigger?
Initially, yes.
A small tax generates small revenue.
A medium tax generates larger revenue.
But.
There is.
As the tax gets very large, it distorts behavior so much, shrinking the market quantity so drastically that the tax revenue actually starts to fall.
So a super high tax rate could bring in less money than a moderate one.
Precisely.
You reach a point where the high rate kills off so many transactions that even though you're taxing each remaining transaction heavily, the total revenue declines because the number of transactions has plummeted.
That relationship revenue first rising, then falling as the tax rate increases.
That sounds familiar, isn't that the.
The Laffer curve.
Exactly.
Arthur Laffer famously illustrated this idea, supposedly on a napkin back in 1974.
And the implication was controversial, right?
That maybe some tax rates were already too high on the downward sloping part of the curve.
That was the suggestion.
The cutting taxes could perhaps counterintuitively increase government revenue by boosting economic activity so much.
Did economists buy it?
Well, most were skeptical about it applying broadly in the U .S.
at that time.
But the idea gained political traction, especially with Ronald Reagan.
Why Reagan?
He had personal experience during World War Two with extremely high marginal tax rates, like 90 percent.
He claimed he just stopped making movies after hitting that bracket because it wasn't worth it.
So he believed high taxes discouraged work deeply.
It became a key part of his supply side economics platform in 1980.
Cut taxes to encourage work and investment, boost the economy and maybe even raise revenue.
And did it work?
Did the Reagan tax cuts increase revenue?
That's still debated.
It's very hard to isolate the effect of the tax cuts from everything else happening in the economy.
It's like an impossible experiment.
So no firm consensus?
Not really.
Some economists think tax cuts might raise revenue if they're targeted at extremely high rates, like maybe Sweden's 80 percent rates back in the 80s.
But for more typical rates, cuts usually mean less revenue, at least initially.
What's the general agreement then?
The key point economists agree on is that you have to consider behavioral effects.
How do people react to the tax change?
You can't just do simple arithmetic on the rates.
And this idea is still relevant.
Laffer advised Trump too, right?
He did, advocating for the 2018 tax cuts, predicting strong growth and no deficit increase.
And the outcome?
Well, the early evidence seems to suggest the skeptics were more accurate.
There was some growth, but also lower revenue and a larger deficit than predicted by the supply -siders.
So quite a complex picture.
We've covered a lot of ground here, from the basic idea of a tax wedge.
To measuring lost welfare through deadweight loss.
Understanding how elasticity determines the size of that loss.
And exploring that really interesting Laffer curve relationship between tax rates and revenue.
The big takeaway seems to be that taxes have costs beyond just the money transferred to the government.
They change behavior, they shrink markets, and they lead to this deadweight loss, of potential gains.
Exactly.
That inefficiency, that deadweight loss, grows surprisingly fast as taxes get bigger.
And the size of that loss really hinges on how much people and businesses react to their elasticity.
Which leads right back into those debates about labor taxes and the size of government.
And finally, the Laffer curve reminds us that extremely high tax rates can actually be counterproductive, even from the government's own revenue perspective.
It really forces you to think about the behavioral side of taxation.
It certainly does.
Maybe the next time you encounter a debate about raising or lowering a specific tax, you'll think not just about fairness, but also about the likely size of the deadweight loss.
And, well, where we might be on that Laffer curve for that particular market.
That's a great way to think about it.
Thanks for joining us for this deep dive into the often hidden costs of taxation.
We really appreciate you exploring these economic ideas with us.