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  • Welcome to Crash Course Economics, I'm Jacob Clifford.

  • And I'm Adriene Hill. We've been talking a lot about macroeconomics: GDP, unemployment,

  • fiscal and monetary policy. That kind of thing. Now we're going to start talking about microeconomics.

  • Microeconomics looks at individual markets and the decision-making of consumers, businesses,

  • and governments. They answer questions like, "How many workers should we hire?" or

  • "Is increasing minimum wage and good idea?" and "Why is health care so expensive?"

  • Now you might be thinking, which is more important: micro or macro? The answer is (BOTH) micro/macro.

  • Actually (BOTH) macro/micro. They're both important.

  • [Theme Music]

  • Let's start with one of the most important concepts in microeconomics: marginal analysis.

  • For economists, the word "marginal" is pretty much the same as "additional". Marginal analysis

  • looks at how individuals, businesses and governments make decisions. Basically, they're interested

  • in additional benefits and additional costs.

  • Businesses do the same thing when they decide how many workers to hire. They compare the

  • additional revenue that an additional worker will likely generate for their company. And

  • to the additional cost of hiring that worker: wages and benefits.

  • If hiring that worker brings in more marginal revenue than marginal cost, then, congratulations!

  • Someone's got a job!

  • This also applies in the realm of how people feel about things. Take the development of

  • city parks: citizens obviously get more total satisfaction from, like, four city parks than

  • from only three. But that doesn't necessarily mean that the government should build four parks.

  • Instead, the government looks at the additional benefit or satisfaction generated by the fourth

  • city park and compares that to the additional cost and here, when we're talking about cost

  • we're talking about the use of city land, and the tax money spent on building the park.

  • If the additional benefit is higher, then they build the park. The government keeps

  • doing this for each additional park. The benefit of the first park is higher than the additional

  • benefit of the second park, and on and on.

  • Eventually, the marginal benefit of another park will be less than the marginal cost,

  • so they stop building parks.

  • Sure it's nice to have lots of parks, but the difference between having 200 parks and

  • 201 parks is pretty small. This is the Law of Diminishing Marginal Utility. By the way,

  • when economists talk about consumers, the word 'utility' means 'satisfaction' or happiness

  • people get from consuming a good, or service, or 201 parks.

  • So you could reword this as the Law of Decreasing Additional Satisfaction, as you consume additional

  • amounts of anything, you'll eventually get less and less additional satisfaction.

  • It's like how the first slice of pizza or cookie that you eat, is awesome, and the second

  • one might be even better, but eventually, each additional one gives you less additional enjoyment.

  • Economists have even made up a new word to help quantify satisfaction called 'utils'.

  • Utils are like happiness points and they are completely subjective.

  • So one person might get 100 utils of satisfaction from the first slice of pizza and another

  • person might only get 10 utils.

  • So the ideas here make sense, right? But the whole numbers thing, this 'utils' idea it

  • does seem a little contrived. People don't actually make these calculations, do they?

  • Yeah, they do. You don't write them down or think about your happiness in terms of utils,

  • but you do likely unconsciously use marginal analysis every day.

  • Let's go to the the Thought Bubble.

  • Marginal analysis can explain all sorts of human behaviour. Let's say that Stan goes

  • to an amusement park. He's unlikely to ride the best ride in the park, the tallest rollercoaster,

  • over and over and over, the entire day.

  • Why? Well even if there's a one-time park admission fee and the rollercoaster is free,

  • there's still a cost - that's how long he has to wait in line.

  • So Stan estimates his marginal utility of riding the ride and compares that to the wait.

  • Riding the best rollercoaster might give him the highest utility of all the rides in the

  • park but it might not be worth waiting in a four-hour line.

  • A smaller ride gives him less utility but if the line is super short, he'll choose that

  • one instead. Even if there's no line for the large super-awesome rollercoaster, he probably

  • won't ride it all day because eventually it gets old.

  • Marginal analysis explains the behaviour of consumers like Stan, but it also explains

  • the pricing strategies of businesses.

  • Assume instead that the rollercoaster charges $5 for each ride. Because Stan gets less and

  • less utility each time, he might not be willing to pay full price for the third ride

  • The seller gets this, and figures it might be better to charge Stan less for the third

  • ride. That's why we have deals like 'Buy two and get the third half off'. The point is

  • we all use marginal analysis when we make decisions.

  • Thanks, Thought Bubble. So that's marginal analysis. Armed with our new knowledge, let's

  • go back and look at the most important model in microeconomics: supply and demand, on the runway.

  • Let's use the market for strawberries. Remember, the price of strawberries is on the vertical

  • axis, and quantity is on the horizontal axis.

  • The demand curve for strawberries is downward sloping,showing the Law of Demand. When prices

  • are high, people don't wanna buy very many, and when prices are low, people want to buy a lot.

  • The shape of the demand curve reflects the idea of the law of diminishing marginal utility.

  • The first pint of strawberries you buy give you a lot of additional utility.

  • The second one, maybe not as much. And the third pint, even less. If you eat ten pints,

  • you're gonna get sick. So, as you consume more, you're willing to pay less and less.

  • This explains why the demand curve is downward sloping and why it's really just a marginal benefit curve.

  • The supply curve is upward sloping representing the Law of supply an increase in price gives

  • producers an incentive to produce more.

  • It turns out that supply curves are really just marginal cost curves. It represents the

  • additional amount of resources and energy that each additional pint of strawberries

  • costs. This graph explains why markets tend to be so efficient with ours scarce resources.

  • If strawberry producers produced too few strawberries, the marginal benefit of the last unit will

  • be greater than the marginal cost. That's the market calling out for more strawberries:

  • "Give us strawberries, please!"

  • If they produce too much, out here, then the marginal cost would be greater than the marginal

  • benefit, they'd be wasting resources on things that consumers don't value.

  • Equilibrium is efficient because the marginal benefit of the last unit consumed equals the

  • marginal cost of that unit. The market is making the exact amount that consumers want.

  • This is reminiscent of an example Adam Smith used. Why are diamond more expensive than

  • water? Water is absolutely crucial for keeping us alive, while diamonds do nothing except sparkle. But

  • the price of a bottle of life-giving water is around a buck twenty and that's when you're overpaying for water.

  • The average one-carat diamond is well over $3,000. This is called the Diamond Water Paradox,

  • and it can be explained with marginal analysis and the law of diminishing utility.

  • The total utility we get from water is VERY high, but since it's so plentiful for most

  • people, the marginal utility is really low. If you can stay hydrated, cook, take showers,

  • wash your clothes and occasionally use your slip 'n' slide, then the additional satisfaction

  • of yet another gallon of water is small. The result is a lower price.

  • On the other hand, diamonds are extremely scarce because they have to be extracted from

  • expensive, dangerous, mines. Since there are relatively few diamonds, the additional satisfaction

  • of another one is relatively high, so people are willing to pay a higher price.

  • If diamonds fell out of the sky like water, we wouldn't get that much additional satisfaction

  • from them, and the price would be low. It might seem irrational that society values

  • diamonds more than water, but using marginal analysis, it sort of makes sense.

  • Relative scarcity does contribute to a product's value - that's partially why Action Comics

  • number one, the first comic book with Superman recently sold for over for over £3m on eBay,

  • but just because something is limited doesn't automatically make it valuable.

  • There are plenty of other things that are scarce that we don't value as much as diamonds.

  • For example, panda boogers. They're super-rare, but we don't put them on engagement rings

  • or pay an outrageous price for one in mint condition.

  • The point is, utility is subjective, and demand depends on the tastes and preferences of consumers.

  • That's why there's no market for panda boogers.

  • Hold on, Stan tells me that, because the internet, there does seem to be a market for panda boogers.

  • But it's gotta be a small one. I think the example still holds up.

  • Anyway, the demand also depends on the number of substitutes. For example, strawberries

  • have plenty of substitute goods - cherries, raspberries, blueberries. When the price goes

  • up for strawberries, consumers buy less because they'll go buy something else instead.

  • This is a substitution effect and along with the law of diminishing marginal utility, it helped shape the demand curve.

  • Let’s see what this looks like in the real world. Have you ever wondered why gas stations

  • don’t have sales? It has to do with substitutes and what economists call elasticity of demand.

  • Elasticity shows how sensitive quantity is to a change in price, when the price of gas

  • goes up people don’t buy that much less gas because they need it and there are few close substitutes.

  • Now you can walk, or ride your bike, or get an electric car but there is nothing else

  • you can put in your current gas guzzler, this goes the other direction too, if gas stations

  • had sales, consumers wouldn’t buy that much more gas. Economists would say that the demand

  • for gasoline is relatively inelastic: a large percent change in price leads to a small percent

  • change in the quantity demanded.

  • This is shown on the graph by making the demand curve steeper, other products that have that

  • have relatively inelastic demand include electricity, healthcare and coffee, there’s no substitute

  • for my five cups of coffee in the morning.

  • And there are few products that have perfectly inelastic demand, if the price goes up people

  • who can afford it will always buy the same amount, an example is insulin for diabetics

  • because in that case they need it to live.

  • What about the demand for pizza? Well there are many close substitutes, I could eat a

  • burrito or a burger, I don’t really need pizza. So a small increase in the price could

  • cause the price to decrease a lot, for pizza the demand curve would be more flat, showing

  • the demand for pizza is relatively elastic. If a pizza place has a sale a lot of customers

  • would buy pizza instead of other substitutes like burgers and burritos.

  • Now there’s also elasticity of supply. A steep curve shows the supply is relatively

  • inelastic, so a large change in price, leads to a small change in quantity. Like an airplane

  • is difficult and time consuming to build, so even if a buyers willing to pay more for

  • one, theyre still going to have to wait.

  • Relatively elastic supply is when quantity is sensitive to a change in price because

  • producers can respond quickly, stuff like t-shirts and strawberries. Something like

  • the supply of Vincent Van Gogh paintings, well that’s perfectly inelastic because

  • when the price goes up, the quantity doesn’t change. It doesn’t matter if people want

  • more, Van Gogh is not going to be doing anymore paintings.

  • So that’s microeconomics in a nutshell, it doesn’t focus on GDP or on unemployment,

  • it analyses the details. It’s helpful to understand concepts like marginal analysis

  • and elasticity. Youre going to be using them to make decisions anyways so you might

  • as well understand what’s going on. Ideally thatll help you make better decisions.

  • We hope the additional benefits of watching this video was greater than the additional

  • cost. I’d say it was at least 50 utils for me.

  • And not that it’s a util contest but I’d say 55 utils. See you next week

  • Crash Course Economics made by the help of all these nice people. If youre still watching

  • the credits, your demand for this video is just about to outstrip the supply, but you

  • can create more supply when you support Crash Course at Patreon, youll help keep Crash

  • Course free for everyone, forever and get great rewards. Thanks for watching and I hope

  • you got some utils out of this.

Welcome to Crash Course Economics, I'm Jacob Clifford.

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邊際分析、雲霄飛車、彈性和梵高:經濟學速成班 #18 (Marginal Analysis, Roller Coasters, Elasticity, and Van Gogh: Crash Course Econ #18)

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