The second degree price discrimination is the most interesting one.
Sometimes the seller knows that there are
different kinds of consumer but cannot tell them apart.
So, cannot separate the consumers into groups.
This would be very difficult because we do not know
which consumers to pick for one group and which to pick for the other group.
However, it is possible if you are smart enough
to discriminate to charge different prices by setting up
creating self-selection mechanisms and mechanisms that
will make consumers so that themselves they will choose the right group.
How does this happen?
You create different versions or different bundles or different sets of products so that
consumers by themselves will join the appropriate group
where they belong to voluntarily by themselves.
This is the critical difference between
the second degree price discrimination and the third degree price discrimination.
In the third degree you separate the consumers,
in the second degree consumers self select which group they will join.
Now, the natural question that you can ask is why should I join?
Why should I ever want to join the expensive group?
Wait a second and you will see why you might cover reasons to indeed join
the expensive group and why actually
you already have done that several times in your life.
So, the mechanisms have to be what we call in game theory separating,
meaning that every consumer should want to join
the group that is intended is designed is created for these specific consumers.
If they are not separating in other words they are pooling,
this means that all consumers will want to join one group,
so creating groups would be not working so nicely for you because
it means that you didn't create them
correctly or you didn't have sufficient reasons to create them.
So, mechanisms must be separating,
every consumer should join the group that is intended specifically for them.
Assume we have only two consumer types.
The enthusiasts, as I love to call them, and the usuals.
So, they will have some people that they like
the product more they are enthusiastic about
the product and some consumers that they just like the product as usual,
not that much, they will still buy it if it's in
the right price but they are not that crazy about this product.
Now, enthusiasts have a different demand than usual,
this is what separates the two groups.
So, if this is our graph about demands,
this would be the demand for usuals and this will
be the demand for enthusiasts, enthusiasts,
they like the product more and therefore their demand
is higher than the demand of the usual consumers.
Again, here we have an informational problem,
that the firm cannot tell if a consumer is E or U,
if he's an enthusiast or if he's a usual.
If it was up to you and they would just charge you different prices
by just asking you and you go into the store and they tell you,
''So, what are you?''
And I would say if I say that I'm enthusiastic which I am,
I'll have to pay a higher price, I'm a usual.
Okay, so you have reasons to not reveal your true type,
the firm will have to do something to take this information out of you voluntarily.
Let's see how this can work.
And we're going to use the two part tariff that we used before.
So, this means that consumers will pay
a participation fee plus a price for a unit that they will be charged.
First of all, notice and it's very crucial
it's a little tricky here so be very very careful now,
that if you have a single two part tariff but two different consumers,
it will be impossible to get the entire consumer surplus.
You cannot capture the entire consumer surplus anymore.
Now, you're going to capture just more than in monopoly but not all of it in any way.
So, we have two choices.
If we charge A to be equal to the surplus of the enthusiasts,
enthusiasts have a high consumer surplus which
means that the entry fee will be expensive.
If you do that, enthusiasts will join,
but usuals will not be able to join this market.
They will not be able or willing to pay S_E as a participation fee.
Your other option is to charge a participation fee and entry fee
equal to the consumer surplus of the usuals.
This means that everyone will be able to buy,
this will be cheap for enthusiasts,
enthusiasts will enter and they will also have
a surplus because they were willing to pay more,
but also now, your usuals will be able to join.
These are the only two alternatives that you have.
If you charge any A between these two S_E and S_U,
then this is an irrational choice because you're just losing profit.
There's no reason for you because they are no different consumers,
consumers are no different,
like gradually different, consumers are of just two different types.
You either charge the high surplus or the low surplus,
any surplus in between is just waste of money for you.
So, if the demands of the two different groups,
the enthusiasts and the usuals are far apart,
they're separated a lot,
this means that the surpluses that these two groups will have,
they will be much much different also.
In this case, you may need to proceed by not serving the market of usuals at all.
And this is because in order to price in the usuals,
you will have to drop your participation fee very
low and you will lose a lot of money from the enthusiasts.
So, if you don't want to do that and probably if are sufficiently far apart,
the two demands, you will want to just serve one group,
do not price discriminate at all.
The other group will see the expensive price and will just not join by itself.
In this case, you will set the price equal to the perfectly competitive price equal to
the marginal cost because you are already
capturing the entire surplus of your enthusiasts.
Now, if the consumer types are very similar and
the demand curves of the two groups are close together,
then in this case, you might say wait a second they're not that different so
maybe with just going a little bit
lower and charging a higher unit price
but going a little bit lower with my participation fee,
I will be able to price in everybody.
So, we'll have more customers if
my cost structure and everything is allowing for that then to
have the capacity why not for going for for more customers.
So, this would be a profit maximizing solution.
So, if the consumer types are similar,
then we may want to charge a little higher price than marginal cost,
and then A will be equal to the surplus of the usuals,
so everybody can be priced in.
Natural question again, how is this price discrimination?
Why is it price discrimination?
Why? They do not have different prices.
You end up charging
one single two part tariff same participation or
entry fee for everybody and same unit price for everybody.
How is this price discrimination?
You do not have different prices per group.
The entry fee is cheaper for if you want to serve both kinds.
So, you will go with S_U which is smaller than S_E.
And you'll price little more than marginal cost if you decide to serve both of them.
So, enthusiasts will end up paying more,
and the reason is that they will buy higher quantities as usually.
So, they effectively will pay
a lower average price because the participation fee will be split among more units,
but in the end,
their total expenditure for the product will be
higher because the price is higher than the marginal cost.
On the other hand,
usual consumers buy less therefore
effectively they pay a higher average price because the participation fee will be
divided among less units and then overall they will end
up to have lower expenditures so they will be able to afford to buy some of the product.
Stay with us because now,
we have a very interesting case about
the Polaroid instant cameras and how they change the world of photography,
not because of the invention but because of the genius pricing method that they applied.
Just stay with us.
Kosmas MarinakisAssistant Professor
