May 3rd, 2004
[NOTE: This page can be downloaded
as a Word document.]
The Monopoly Politics 2004 report contains two spreadsheets. The first,
complete spreadsheet, makes projections in the
2004 House races in an Excel format.
The second, Monopoly Politics 2004, makes projections for each House race
in an easy to read html format.
This user's guide describes how to modify the parameters in the
complete spreadsheet model and analyze their impact on the projections.
The spreadsheets use the same algorithm for making projections.
For details of the model, check out the file, algorithm.doc, which
explains each parameter in greater detail.
If you have questions or problems with the spreadsheet, please
Center for Voting and Democracy
Monopoly Politics 2004 Projections
You can do 4 things with this spreadsheet:
Modify parameters to examine their impact on projections
Enter 2004 results
Views summaries of projections by category and party
View summaries of the accuracy of the projections
1. Modifying parameters
The spreadsheet contains all of the data used to make
projections: partisanship of the
district, which seats are open seats, date of election of incumbents, and prior
2 election results.
It also contains the following parameters that the user can
modify by typing a new number into the specified cell:
|Buffer for open seats
|Increase for "underachieving" first-termer
|Decrease for "overachievers" new incumbents
|Absolute reduction for "underachieving" incumbent
|Decrease if previous race uncontested
|Decrease for "overachieving" incumbent
|Adjustment to better 2nd election
|Dem 2-party share
If you enter a value outside of the range of a parameter, the
projections may not be meaningful.
2. Enter 2004
The spreadsheet is set up so that you can enter the winning
party (D, R or I) and percent in columns V and W, rows 21 to 455.
Once you do that, summaries showing the accuracy of the projections will
Be sure to enter the winning percentage as a percent (ie, 43.7%,
not 43.7, which would appear as 4370%). To
enter a party, use a capital letter: D,
R or I.
summaries of projections
A variety of summary information about the projections appears
in yellow-shaded cells in columns N-P and Q-T in rows 8 to 16 of the
Total number of projections by category
number of projected landslide victories.
number of projected comfortable victories.
Tight: The number
of projected close wins.
number of "vulnerable” incumbents.
number of districts in which we do not project a win.
Other: This is a
check for errors. It is the number
of districts that do not fall in the above categories.
If it is not zero, there is a problem with the model or the parameters.
Please contact the Center if this happens.
Projections by party
This table shows the projections by category for seats held by
each party. These figures are based
on the incumbent party, and since this is a redistricting year, some of the new
seats don’t have incumbent parties. Also,
one seat (VT-1) is held by an Independent. That’s why the total number of
seats is less than 435.
summaries of the accuracy of projection
Columns V-W: Totals of vulnerable, losing
and open seats
lists the number of projections labeled as “Vulnerable” and, once data
on the 2004 results is entered, the number of those incumbents who lost.
Losers (not open): After
2004 results are entered, this will show the number of losing incumbents.
Open seat party changes: The
number of open seats whose party changed as a result of the 2004 election.
Open seats: The
number of open seats this year.
Accuracy of projections by category
These columns remain zero until 2004 results are entered.
For each of the projection categories, these columns list the
number of projections in which the party projection was accurate and the number
in which the winning margin was correct.
Results of races by prediction category
For each prediction category, these columns show the number of
races that ended up being landslide, comfortable, wins or losses (from the
perspective of the incumbent party).
The cells highlighted purple indicate races where the winning
margin or party was wrong.
For example, with the default settings, there are 100 projected
comfortable races. After entering
the results (party and winning percent) from the 2004 races in column N and O,
you will see in columns V-Y the results in the 100 projected comfortable races.
Some of those races will be won by landslide, others by comfortable
margins and others by less than comfortable margins. Any
remaining races in this category would be losses for the incumbent.