Game Development Reference
In-Depth Information
We could have addressed this without flipping the axis as we did above. The
same idea can be represented by going the opposite direction on a marginal util-
ity curve. If moving left to right on a graph gives us decreasing marginal
utility, then moving right to left represents increasing marginal utility. Often,
the choice of which direction to express a utility curve will depend on what the
predominant usage of it will be.
Marginal utility is used for more than just determining the relative importance of
things we are either acquiring or already have (such as the soldiers and health).
Marginal utility can also be used to weigh things that we are either giving up or
putting at risk.
For example, each additional dollar of our money that we spend has an increas-
ing marginal utility. While we may be willing to spend our first or second dollar, we
may not be as enthusiastic about spending our last dollar. Along the way, each ad-
ditional dollar that we spent meant more and more to us.
In the example of purchasing the warranty for a computer in Chapter 7, one
question that was never addressed but is relevant in an intriguing sort of way is
“How much money do we have in the bank?� We aren't simply talking about
whether we can afford to purchase the warranty in an absolute sense, that is,
whether we have that extra $600 over and above the cost of the computer itself. We
are addressing something a little more ephemeral. We want to know what that
extra $600
means
to us.
When Pascal cautioned us that we “need to know what is at stake,� there was
more to it than a simple value measurement of the wager alone (in this case, the
dollar amount of the warranty). Not only do we have to consider the relative value
of the wager to the potential outcome, but we must consider the value of the wager
itself relative to what we can
afford
. If money is tight, a person may opt to not take
the extra cost of the warranty and instead take his chances on getting through that
first year unscathed. The value of the money saved by not buying the warranty
might be needed elsewhere. To use a rather obvious example, rather than purchas-
ing the warranty to guard against the
possibility
that we might need it, we may choose
to keep the money to fund the
extreme likelihood
that we will want to purchase food
in the next 12 months.
Conversely, a multimillionaire would probably not bother with the hassle of a
warranty on this computer. To him the replacement cost is negligible. (One could
make the case that a multimillionaire should be buying a better computer than the
