April 10, 2020
Lec 1 | MIT 14.01SC Principles of Microeconomics

Lec 1 | MIT 14.01SC Principles of Microeconomics


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MIT OpenCourseWare at ocw.mit.edu. PROFESSOR: So what I want to
do today is I want to talk about what the heck
this course is. What is microeconomics? What are you going to be
learning in this course? And just, sort of, set us
up for the semester. OK. So basically, microeconomics
is all about scarcity. It’s all about how individuals
and firms make decisions given that we live in a world
of scarcity. Scarcity is key because
basically what we’re going to learn about this semester in
various shapes and forms is a lot of different types of
constrained optimization. We’re going to learn a lot
about different ways that individuals make choices
in a world of scarcity. OK? That is, this course is going
to be about trade-offs. Given scarce resources, how
the individuals and firms trade off different alternatives
to make themselves as well-off
as possible. That’s why economics is called
the dismal science. OK? It’s called the dismal science
because we are not about everyone have everything. We’re always the people who
say, no, you can’t have everything. You have to make a trade-off. OK? You have to give
up x to get y. And that’s why people
don’t like us. OK? Because that’s why we’re called
the dismal science, because we’re always
pointing out the trade-offs that people face. Now, some may call it dismal,
but I call it fun. And that may be because of my
MIT training, as I said I was an undergraduate here. In fact, MIT is the perfect
place to teach microeconomics because this whole institute is
about engineering solutions which are really ultimately
about constrained optimization. Indeed, what’s the best
example in the world we have of this? It’s the 270 contest. Right? You’re given a pile of junk,
you’ve got to build something that does something else. That’s an exercise in
constrained optimization. All engineering is really
constrained optimization. How do you take the resources
you’re given and do the best job building something. And that’s really what
microeconomics is. Just like 270 is not a dismal
contest, microeconomics is not to me a dismal science. You could think of this
course like 270. But instead of the building
robots, we’re running people’s lives. OK? That’s, kind of, the
way I like to think about this course. Instead of trying to decide how
we can build something to move a ping pong ball across a
table, we’re trying to decide how people make their decisions
to consume, and firms make their decisions
to produce. That’s basically what’s going
to go on in this class. OK? And that’s why basically modern
microeconomics was founded at MIT in the 1950s
by Paul Samuelson. The father of modern economics
was a professor here, and he basically founded the field. He basically introduced
mathematics to economics. And through teaching this
course, 14.01, 50, 60 years ago, actually developed the
field that we now study. Now, what we’re going to do in
this class, is focused on two types of actors in the economy: consumers and producers. OK? And we are going to build models
of how consumers and producers behave. Now,
technically, a model is going to be a description of any
relationship between two or more economic variables. OK? That’s a model. A description of any
relationship between two or more economic variables. The trick with economics, and
the reason many of you will be frustrated during the semester,
is that unlike the modern relationship between
say energy and mass these models are never precise. They are never accurate
to the 10th decimal. OK? This is not a precise,
scientific relationship with modeling. We’ll be making a number of
simplifying assumptions that allow us to capture the main
tendencies in the data. That allow us to capture the
main insights into how individuals make consumption
decisions and how firms make production decisions. But it’s not going to be as
clean and precise as the kind of proofs you’re going to be
doing in some of your other classes in freshman and
sophomore year. OK? So basically, we have a trade
off with the simplifying assumptions. On the one hand, obviously we
want a model that can explain reality as much as possible. If a model can’t explain
reality, it’s not useful. On the other hand, we need a
model that’s tractable, a model that I can teach you
in a lecture or less. OK? And basically, what we do is we
make a lot of simplifying assumptions in this class to
make those models work. And yet, what we’ll find is
despite these assumptions, we’ll come up with incredibly
powerful predictions of how consumers and producers
behave. So with consumers what we’re
going to do is, we’re going to say that consumers are
constrained by their limited wealth or what we’ll call
their budget constraint. And subject to that constraint
they choose the set of goods that makes them as well
off as possible. OK? That’s what we’re going to call
utility maximization. We’ll say the consumers maximize
their utility, consumers are going to maximize
utility subject to a budget constraint. That’s going to be what
we’re going to develop the consumer decision. They have some utility function
which is going to be a model of their preferences. OK? So I’m going to propose to take
everything you love in life and write it down
as a u function. OK? Then I’m going to propose you
take all the resources at your disposal, write them down as a
budget constraint and then I just do constrained maximization
to solve for how you make decisions. Firms, on the other hand, are
going to maximize profits. Pi is profits. Firms are going to
maximize profits. Their goal is to make as much
profit as possible, to earn as much money as possible. OK? However, that’s going to be
subject to both the demands of consumers, we get to firms it’s
a lot harder, subject to both consumer demand
and input costs. So firms have to consider,
consumers have to consider look what does stuff cost
and what do I like, I’ll make my decision. Firms is a little more
complicated. They’ve go to consider, what do
consumers want and how do I make what they want? So they’ve got to consider both
the output side, what a consumer is going to want me to
make and what’s it going to cost me to produce that good? And how do I combine those
to make the most profits? OK? So from these assumptions, we
will be able to answer the three fundamental questions
of microeconomics. OK? The three fundamental questions
of microeconomics will be, what goods and services
should be produced? What goods and services
should be produced? How to produce those
goods and services? And who gets the goods
and services? What goods and services
get produced? How to produce those
goods and services? And who gets them? And what’s amazing, we’ll learn
in this course, is that all three of these questions,
the three fundamental questions that drive our entire
economy, are all solved through the role of
one key state variable, which is prices. Prices in the economy resolve
all of these problems. OK? Consumers and firms will
interact in a market, they’ll interact in a marketplace. And out of that marketplace will
emerge a set of prices, in a way we’ll describe. And those prices will allow
firms and consumers to make the relevant decisions. OK? So let me just give you one, and
we’re going to do all this rigorously throughout the
semester, let me just start with one casual example. OK? Let’s think about the
development of the iPod. OK? Let’s cast our minds way back,
lo way back to the development of the iPod. OK? Now, when Apple was thinking
about making the iPod, they had to ask, would consumers
want this? So consumers had to decide given
their limited resources, given the fact that they were
buying a certain set of things would they be willing to forsake
some things they were already doing to spend the
money on the iPod? OK? It was a non-trivial
amount of money. Would they be willing to
forsake things they are already doing? OK? To spend money on the iPod. And clearly they were. Clearly, consumers were willing
to spend money, to spend a lot of money,
to get an iPod. They were originally
what? $300 Back when $300 meant something. OK. So basically, what the firm will
do is they’ll say, OK, we get a signal from the consumer
that they’re willing to pay money to get the iPod. They’re willing to pay a high
price to get the iPod. Now, the firm will say, well,
should we make iPods? Well, that will depend on what
it cost to make them. So we have to then assess what
are the inputs that we’ll need to make an iPod? Well, to do that we have to
look at the prices of the various inputs that we’ll need,
of the chip in them and the metal and all the other
stuff that goes into the iPod. OK? So they can shop across
different countries, to different kinds of chips, they
can look at different kinds of monitors, et cetera. But, once again, what they’ll
do is they’ll use the prices of those different inputs
to decide how to produce the iPod. So whether to produce the iPod
will depend on the price people are willing
to pay for it. How to make the iPod will depend
on the prices that firms have to pay for the chip
and the casing and all the other things that go
into the iPod. OK? And then finally, who’s
going to get the iPod? Well, they’re going to make
a certain amount. What decided who gets them? Well, the person who gets them
are the people who are willing to pay the price that Apple
decides to charge. Some people are willing to pay
that price, they’re going to get an iPod. Some people are not willing to
pay that price, they will not get an iPod. So the price in the market will
ultimately decide who gets the iPod, as well. OK? So basically, prices will
determine what gets produced, how it’s produced,
and who gets the goods that are produced. OK? Of course, this is a very, very
simplified example, as you can already tell. There are lots of cases
where prices don’t decide these things. So my favorite example is the
fact that there are lines for hours to get tickets to see
a Lady Gaga concert. OK? Now if it’s really true that
prices determine everything, we shouldn’t see any lines. It should just be that those
who are willing to pay the most to see Lady Gaga should. Those who want the most
to get Lady Gaga should get the tickets. Those who aren’t willing to pay
shouldn’t get the tickets. Why should there be a line? Not to mention the fact that
people shouldn’t be willing to pay anything, but that’s
a different issue. That’s a taste issue. We’ll come to taste later. OK? So basically, clearly this
is not working perfectly. If the world worked in the way
I just described, then what should happen is there should be
essentially an auction and whoever is willing to pay the
most for Lady Gaga tickets would get them. And whoever is not willing
to pay wouldn’t. It wouldn’t involve
any waiting in line or other things. Now, what’s very interesting
is we’ve actually seen an evolution from my youth to
your youth towards the economic model. When I was a kid, if you wanted,
so then it was Cars tickets, OK, to date myself, OK,
you had to go and camp out at 3:00 in the morning outside
the store where they’re selling them to get
the tickets. Now, of course, you don’t
do that anymore. Now you go on Stub Hub or
Ticketmaster or these other secondary sellers and there
there are prices that determine it. So how many people have
waited on line to get a concert ticket? That’s amazing. So if I asked this question 30
years ago, 90% of the hands would have gone up. OK? So what that means is the
price mechanism has started to be used. It has replaced the line
mechanism as a way to allocate those tickets. And we see prices working. That wasn’t true. There wasn’t StubHub. There weren’t these secondary
ticket sellers 30 years ago. You had to wait on line
to get the tickets. Now, so that’s basically, sort
of, an overview about, sort of an example, of how we think
about the role of prices. Now, let me draw a couple of
important distinctions, terms I’m going to use this semester
that I want you to be comfortable with. OK? The first distinction I want to
draw is between theoretical versus empirical economics. Theoretical versus empirical
economics. OK. Theoretical economics is the
process of building models to explain the world. OK? Empirical economics is the
process of testing those models to see how good
a job they do in explaining the world. OK? We could all make up a model. OK? Anybody with math skills
could make up a model. But it doesn’t do any good
unless it’s actually doing something to explain
the world. And so basically, the goal of
theoretical economics is essentially to build a model
that has some testable predictions. To build a model that says,
look here’s my simplified model of how consumers decide
whether or not to buy an iPod. OK? I have a model of that, that
I’ve built theoretically. Well, that has some testable
predictions. And the role of empirical
economics is to gather the data and go and test them using
statistical methods. Specifically, typically
regression analysis like the kind you learn about in
advanced statistics. OK? So basically, what we’re going
to do is we’re going to is 95% of this course will be
about theoretical economics this semester. It will be about understanding
how economists develop the models to model how consumers
and firms behave. But I will try to talk somewhat about
empirical economics and what data we can bring to bear to
understand whether or not these models explain
the world. OK? The other distinction that’s
very important is positive versus normative economics. Positive versus normative
economics. And this is the distinction
between the way things are, which is positive economics, and
the way things should be which is normative economics. Distinction between the way
things are and the way things should be. OK? So let’s consider a great
example of microeconomics at work which is auctions
on eBay. OK? Auctions on eBay, economists
love studying auctions on eBay because it’s a textbook example
of what we call a perfectly competitive market
which is what we’ll focus on the semester. A perfectly competitive
market. OK? And by that we mean that
basically that producers in this market offer up
their good to a wide range of consumers. OK? A number of producers offer
up their goods to a wide range of consumers. OK? And the consumers bid up the
price until the person who has the highest value for
the good gets it. So price serves exactly
the signal it should in allocating goods. OK? So really eBay’s really sort of
about this third thing of who gets the good. OK? I offer my alarm clock or
whatever on eBay, OK, and then people bid on that. And whoever values that the
most, that rare Jon Gruber alarm clock the most,
they get it. OK? So it’s a perfect textbook
example. OK? And basically, because on eBay
the price is used, or now with also StubHub and concert
tickets, the price is used to allocate the good to the
person who wants it the most. OK? Now, a recent example of an
auction on eBay that a lot of attention, not so recent anymore
a couple years ago, someone tried to auction
their kidney on eBay. OK? Someone offered their kidney for
auction on eBay and said, I have two kidneys
I only need one. So I’m going to auction my
kidney, you pay for me to fly to wherever you need my kidney
and the operation, they take it out and they give
it to you. And that’s the way it goes. So what happened was person
offered their kidney and they said the starting price
will be $25,000. They didn’t do a buy it now. They said the starting price
will be $25,000 and the bidding went on. The price got to $5 million
before eBay shot it down. eBay shut the auction down. And eBay said no, in fact,
you can’t do this. Now there’s two questions
here. The first is, why did
the price of the kidney go so high? That’s the positive question. The positive question is, why
did the price the kidney on eBay get so high? And here, we’ll talk, and you’ll
learn more starting Friday, about the twin forces
of supply and demand. The twin forces that drive the
economy of supply and demand. And you’ll talk more rigorously about these on Friday. Basically, they’re what
they sound like. Demand is how much someone
wants something. Supply is how much of
it there is to have. And the intuition here
is surprising. OK? The more that there’s demand for
a good, the higher will be the upward pressure on prices. The more people want a good,
the higher prices will go. And the less supply there is
of a good, also the higher prices will go. So if everybody wants something
but it’s common, the price will be low. And if no one wants something
but it’s uncommon, the price will still be low,
and vice versa. In fact, the development of the
model of supply and demand framework was from Adam Smith,
the, sort of, so-called first economist who wrote The Wealth
of Nations in 1776 which is, sort of, viewed as the,
kind of, first serious book about economics. And he posed what he called
the water diamond paradox. What Smith said in that book is,
look, it’s clear water is the most important
thing in life. We can’t live without water. And diamonds are completely
irrelevant to life. You can live totally fine
without a diamond. And yet, the price
of diamonds is astronomical and water’s free. How can this be? How can it be that water which
is so much more of a fundamental building block of
our life is so much cheaper than diamonds which are not. And the answer, of course, is
that so far you’ve only considered demand
and not supply. Yes, it’s true. The demand for water
is much higher than the demand for diamonds. But the supply is even larger. So that basically, yes it’s true
that while water should be worth more, in fact, in the
end the price of water is much lower, because of the twin
forces of demand and supply. The demand is higher, but the
supply is much higher. So the price ends up lower. And that was his diamond
water paradox. OK? Well, in this case, it’s
a similar thing. What determines the demand
for a kidney? What determines the demand for
a kidney is going to be the fact that you die without it. OK? If you have no kidneys, you’re
having kidney failure. OK? You’ll die without it. So basically, what will
determine it is people are willing to spend all their
wealth, as much money as they can have, to get a kidney OK? So the demand will
be quite high. The supply will be quite low. Sadly, not many people are
willing to be organ donors. More relevantly, a lot of
people aren’t in good situations to be organ donors. OK? As a result, the supply is much
lower than the demand. So we have a situation with a
high demand, a low supply and the price went through
the roof. That’s a positive analysis. OK? So we can understand
pretty intuitively. We don’t need this course
to understand why the price went up. OK? It’s just the twin powers
of demand and supply. But what about the normative
question which is, should eBay have allowed this
sale to happen? EBay at $5 million cut it off
and then passed the rule saying you can’t auction your
body parts on eBay. OK? Should they have done that? That’s the normative question. That’s economics gets really
interesting, which is you all are smart enough to figure out
why the price went up. But this is where it gets
interesting is should people have been able to auction
their kidney on eBay? On the one hand, many, many
people in this country die for want of a body part. OK? Thousands to hundreds of
thousands of people die every year waiting for a transplant. OK? If someone is incredibly rich
and they want a body part, which to me a surplus because
I have two kidneys, why shouldn’t they be allowed
to buy it from me? I’m better off because they
can pay me a ton of money. They are better off
because they live. So I’ve just described a
transaction that makes both parties better off. Why shouldn’t that be
allowed to happen? So you tell me. Does everyone think
eBay was wrong? Yeah, go ahead. AUDIENCE: Say there is another
person who doesn’t have as much money, and that
person also dies. PROFESSOR: You mean the person
who, what do you mean the person doesn’t have as much- AUDIENCE: –so obviously
somebody doesn’t get the kidney. PROFESSOR: So in other words,
what you’re assuming is, let’s say that if I hadn’t done the
auction on eBay, I would have just given my kidney away to
the transplant center. Then that’s one less kidney
that can go to the transplant center. And that means the rich guy gets
the kidney, and someone else implicitly doesn’t. That’s a trade-off. You’ve just described
a trade-off. The trade-off is that basically
now we’ve allocated the kidney away from the poor
person to the rich person. Now, but why do we
care about that? I mean one person dies,
another person lives, why do we care? Yeah? AUDIENCE: There would
be some sort of case of severity in condition. Like there might be someone
who’s poor who would get the kidney if it went to a
transplant association because they would die in a couple
of days without it. Whereas the rich person might
just be able to afford it, and it might make their life
more convenient. But they might not be
in any more peril. PROFESSOR: They might
be a collector. So basically, that’s right. So one reason we might care is
because we think that kidneys should be allocated on the
basis of who needs it the most. OK? So a great example of this, of
course, was Mickey Mantle with a liver transplant. Mickey Mantle, famous
ballplayer, raging alcoholic, who had liver failure because
he was basically drinking himself to death, and jumped
the queue and got a liver above a bunch, a lot of people
and then he kept drinking and killed himself and wasted
the liver he’d gotten. OK? So basically, you can think
that doesn’t make sense. We should give it to people who
need it the most. For who it would do the most
good in terms of increasing their life. OK. So we’ve got the substitution
point. OK. Let’s come back to the
substitution point though. Tell me a situation in
which that’s wrong. Can someone tell me a situation
in which, in fact, that not a valid point. Yeah. AUDIENCE: Well, if the guy
is only going to sell it. He’s not going to
give it away. PROFESSOR: Exactly. You’re assuming that the
guy who did sell would give it away. But, in fact, if it’s
sell it or keep it then there’s no trade-off. And similar here, if it’s sell
it or keep it then you might as well let the rich
guy get it. Or is there another argument? Is there another reason
why you might not want this to happen? Yeah. AUDIENCE: It would encourage
people to use illegal ways of getting kidneys. PROFESSOR: So the other reason
could be that we don’t trust people to make good decisions
when money’s involved. That we think that, gee, if it’s
really true I can get a couple million bucks for a
kidney, I might give mine up even if I haven’t really
thought through the ramifications of doing so. Even if there’s a risk to the
surgery, if there’s a risk that my other kidney will then
fail then I’ll be screwed. OK? So basically, we might have a
paternalistic attitude that will lead us to not want to
allow people to engage in this kind of risky behavior. Yeah? AUDIENCE: There may also be
some legal ramifications associated with that if someone
sells their kidney and then their other kidney fails,
they might then blame eBay. PROFESSOR: Want it back. Like that Repo movie. That’s right. There could, but let’s leave the
lawyers out of this, OK? I don’t like lawyers. I’m going to rag on lawyers
this semester. We’re going leave the
lawyers out of this. But, in any case,
you’re right. That’s, sort of, a ramification of the same thing. So we’ve talked about the fact
that there’s substitution. We’ve talked about the fact
that it’s not allocated to those who need it the most.
We’ve talked about the fact that people might be making bad
decisions in doing this. But there’s another factor, as
well, which is we may just as a society feel it’s unfair
that rich people can get things poor people can’t. There may be a pure equity
component here. OK? Which is simply that we as a
society value equality, value income inequality. And we think people should not
have an extra shot at getting a resource just because
they’re rich. Now that is a very deep and hard
concept, and we’ll spend a couple lectures talking about
equity towards the end of the semester. By and large, we won’t
consider it. OK? But it turns out to be behind
much of what we’ll discuss, OK, in much of what we’ll
discuss this semester and much of what goes on in economics. OK? Just take a look at the debate
that’s going on right now in terms of President Obama trying
to decide whether or not to extend tax cuts to
wealthy individuals in the US. Some people argue that allowing
those tax cuts would promote the economy. OK? But others argue it’s
unfair for rich people to get tax breaks. And that fairness argument
matters a lot in terms of driving the kind of
economic policy decisions we need to make. So this semester, we’re going
to focus a lot on efficiency and optimization and how
to get resources to the right place. But you have to remember behind
a lot of this is deep normative issues about what
should be happening, how should an economy function, and,
in particular, how should we think about these
kind of equity issues that are so important. OK. The last thing I want to talk
about is I want to talk about why micro is not just an
abstract concept for things like you might say, oh this is
all pretty funny and it’s like selling kidneys on eBay and
tax cuts for the rich and why do I care? OK? Well, you care because literally
every decision you make is made through the kind
of framework we’re going to think about this semester. OK? Now, different decisions may
follow our models more closely and less closely. But there is not an
economic decision. OK? Sorry, let me back up. There’s not a decision that
people have made that economists haven’t
tried to model. From whether to produce iPods,
to how many times to have sex each week. OK? These are all things economists
have tried to model with varying degrees
of success. OK? Because economists think that
these all come from the same decision theoretic framework
that we can discuss. Let’s talk about a simple
example from this course. Your decision of whether or
not to buy the textbook. There’s a textbook and
what’s it cost? $140? What’s it cost? Does anyone know? AUDIENCE: This line says $180. And this one says $180, but
it’s available for $130. PROFESSOR: $130, fine. So $130 for Professor Perloff
out at Berkeley. He doesn’t get it all. I wrote a textbook too. He gets a small share of it. OK. So you have to decide, now has
anyone bought a used version of the fourth, well it’s the
fifth edition now, does anybody use a version of
the fourth edition? Does anyone know what
the used price is? You can be honest.
I don’t care. AUDIENCE: I know some people
found it for like $85 or so. PROFESSOR: So $85. So you’ve got to decide. So let’s say you can buy the
previous edition, the fourth edition, for $85 or the current
edition for $130. OK? You’ve got to make
that decision. OK? How do you make that decision. Well you may think, gee I
just make the decision. It’s not really about
microeconomics. But it is. We’re going to model how
you think about a decision like that. Well how do you think about
a decision like that? Well, the first thing you
consider is your preferences. How much are you willing to take
a chance that there’s new stuff in the fifth edition
that you need to know? OK? If the fifth issue was identical
to the fourth edition then you’d be an idiot
to not just buy the used fourth edition. But it’s not. Textbook writers are smart. They update their book. OK? So basically, the fifth
edition is updated. There’s new things in it. So you have to ask yourself,
what are the odds that I need some of the new information in
the fifth edition and not in the fourth edition? And in thinking about that,
you’re going to think about your preferences. In particular, are you very risk
averse, are you afraid to take a chance? Or are you risk loving? Are you willing to
take a chance? OK? That’s one side of
the equation. If you’re someone that says,
you know I will not take a chance in life. I just have to make sure I learn
the most possible from this course. Then you’re going to want
that new edition. If you’re someone that says, you
know what screw it, I’ll just figure it out later. I’m going to the lectures. I don’t care. OK? Then you might not want
it that much. So that’s the first factor, is
going to be your preferences and break down how much you
are willing to take a risk that you need this
fifth edition. The second factor is going to
be your constraint: how much money you have. OK. The more money you have, the
more you’re willing, or more relevant perhaps your parents
have, the more willing you are to go ahead and buy
that new edition. The less money you have, the
less willing you are. OK? So basically, it’s going to
depend on whether you’re paying or your parents are
paying, in which case what the hell you might as well buy
the fifth edition. OK? And then finally, you’re going
to take these preferences and this constraint, your
preferences and your resources, and go to the market
and look at what does the market tell me the
difference is. So you’re going to say, here’s
how much I kind of care about fifth versus fourth edition,
here’s the resources I have, now I’ll go to the market and
say, aha there is a $45 difference between these
two editions. So now I will solve
that constrained optimization problem. And I’ll decide whether I
want to get that book. You are going to be thinking to
yourself, this is stupid. I never think about
it that way. But the key point is you don’t
have to think about it exactly that way. There’s a famous example in
economics of what’s called the as if principle. I don’t know if kids still
say this one, as if. So it’s the as if principle. OK? And basically it’s from Milton
Friedman, the famous economist from Chicago, who said, look,
when you’re playing pool, technically you could compute
the optimal angles of which to shoot the ball every single time
to get the appropriate bounce and get the balls in. You could do the mathematics
and compute it. But professional pool players
are not in this class with you, I’ll only say that. OK? They’re not guys who are able
to do that computation. They just know how to hit the
ball to get the same outcome they would get if they
mathematically solved for the optimal trajectory
to hit the ball. OK? They behave as if they’ve
solved the constrained optimization problem. And your decision when you buy
this book, you may not think it through the very framework
that I just laid out very heuristically and will lay out
more rigorously this semester. But you’re going to behave
as if you do. Because those facts are going to
be in your mind, and you’ll be thinking about it when
you make that decision. So while you may feel the models
we learn in this course are rather abstract and don’t
really explain how you behave in an everyday basis, you’re
going to behave as if those models are really
applying to you. And if you think about, over the
next few days, think about the decisions you make. From should I bring
an umbrella today, it looks like rain? Well, on the one hand,
I might lose it. It’s a pain to carry. On the other hand, how much do
I care about getting wet? That’s a constrained
optimization decision. To should I have an extra drink
at a party Friday night? On the one hand, that could
have some pros and cons. OK? These are all decisions,
constrained optimization decisions, you’re
going to make. They’re going to affect
your life. And what we’ll learn this
semester is about how you make them and how we model, how
economists can use what we learn about that to understand
the function of the economy. OK? So I’m going to stop there. One other announcement, there
will, in general, be handouts every lecture. I’m not going to
do PowerPoint. I’m going to do handouts. So when you come in every
lecture, please look at the back banister. Though typically, not today. But typically, they’ll be
handouts that you’ll need to follow along with in class. So remember, go to section on
Friday, first problems that will be posted on Friday and it
will be due in section the Friday after. And I’ll see you all back here
on Monday, next Monday.

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