Microeconomics Project
Here is a (draft of a) project I am doing for
a Microeconomics class at Empire State College.
Here is the project:
Possible Problems

If the application doesn't come up
at all,
you will probably need the Java Plugin.
This is available (free) from Sun
at
http://java.sun.com/j2se/1.4.1/download.html.
Click on the appropriate download link under the "JRE"
column. This will get you to the correct
place.

This page works with Microsoft Internet Explorer.
If you are using Netscape Navigator,
then click here.

Sometimes it appears to be taking a while to load.
If you move the mouse over the blank area of the
screen (between the two horizontal rules) it may
speed things up a bit, but I have no idea why.

There can be problems with the graph display.
If the graphs don't look right, hit the
"Update" button, which should
fix the problem.
Abbreviations
 TC  Total Cost
 TR  Total Revenue (= Q * P, both from the demand curve)
 profit = TC  TR
 AC  Average Cost (= TC / Q)
 MC  Marginal Cost (= ΔTC / ΔQ)
 MR  Marginal Revenue (= ΔTR / ΔQ)
 AR  Average Revenue (= TR / Q)
Controls
There are two variables which can be changed:
slope
This is the slope of the demand curve,
which is displayed as the AR,
except when the slope is zero,
when the AR is the same as the MR.
The slope must be a valid (floating point)
number
and must be less than zero.
intercept
For a nonzero slope (a price maker), the intercept
is the place the demand curve will cross the
"Quantity" (xaxis) line.
An increase in the intercept will shift the
demand curve to the right.
However, for a zero slope (a price taker), the
demand curve doesn't cross the x axis, so
in this case, it will be the y intercept, or price.
May I suggest that for a zero slope, a low price (perhaps
around 15) might be more appropriate, since
the graphs do not adjust their scales
automatically.
The intercept must be a valid (floating point)
number
The "Update" Button
Clicking the "Update" Button causes both
graphs to be redrawn. This is very quick.
It can be used after slope or intercept is updated,
or any time that the graph(s) are not properly
displayed.
The Graph Scale
Please note that the "scale" of the
graphs will change as values are changed.
Both graphs will use the same "x"
value, but it may change as the slope or intercept
change.
Each graph has its own value for the "y"
scale. Again, they will change as the inputs change.
Note that this is not a particularly sophisticated
"dynamic scale", but it works pretty well
for most "reasonable" values.