About This Simulation
Purpose of this simulation
How does it work?
How accurate is it?
Credits
Purpose of This Simulation
This simulation is meant to be entertaining and informative for those who are interested in American politics. While it is intended that it be as accurate as possible, given the data available, don’t go and bet anything on its predictions as they are in no way guaranteed.
How Does It Work?
The assumption is made that people will vote the same way they did the last election, except for the changes specified by the user which are applied to each race. The outcome of each Senate and House race is predicted individually. Next, the number of winners for each party is totaled to provide party counts for both the House and Senate.
The calculation is fairly simple. The votes received by the Democratic candidate and the Republican candidate in the previous election are totaled. The percentage of that total received by a party is used as a base percentage for that party in the current election. These percentages are adjusted based on the parameters specified: change in the support for incumbents, change in the support for the parties, and the additional adjustments for when the seat is open or the incumbent is a freshman. Whichever party has the higher adjusted percent for a district is judged to be the winner of that district for the current election.
Importantly, this model does not account for changes in the election results due to voter turnout, the merit of the candidates, nor the effectiveness of their campaigns. The assumption is made that across the country, these effects tend to average out.
For simplicity, it is assumed that the one independent incumbent, Representative Bernard Sanders of Vermont will be reelected. Also, Senators Richard Shelby of Alabama and Ben Nighthorse Campbell of Colorado, who have switched to the Republican Party since their last election, are assumed to take a penalty equal to the percentage lost by a party vacating a seat (the open seat adjustment).
How Accurate Is This Simulation?
With the parameters set appropriately, it correctly predicts the winner in approximately 87% of the House races in the 1994 and 1996 elections. This is not too bad considering it has to cope with a dramatic turn against Democratic incumbents in the 1994 election, the strong shift towards Republican candidates in several Southern states over the last several elections and the redistricting in Georgia, Louisiana, Florida, Kentucky, Maine, and Texas. With no such events foreseen for the 1998 election, it should be even more accurate. No comparative results are available for the Senate since the earliest data used is from the 1992 election and only this year will those Senators be voted on again. The model used is identical to the one for the House.
In general, a model that simple predicts that all incumbents will be re-elected will be fairly accurate. Hopefully, the model used here bests that one. In the end, it doesn’t matter if it predicts the outcome of each individual race correctly, as long as its missed predictions of Republican and Democrat winners tend to balance out. It’s the averages that matter.
Credits
The principal source for election data used is:
from the Clerk of the House of Representatives.
Augmented by special election data from various Secretary of State web sites or, when not available, the Almanac of American Politics.
Source for the status of incumbents:
House
And
Roll Call, and Project Vote Smart.
A thank you goes to Heather Holdridge, head of Project Vote Smart’s Reporter’s Resource Center and my former colleague, for her help with this.
Vote data:
House,
Senate
Thomas
Java slider class to Core Web Programming.
If this program does not appear to work correctly in your browser, I’d like to hear about it. Please identify the type of browser you are using, its version number, and the operating system you are running. Send this information and any other comments or suggestions about this simulation to the author at sl@scottlangley.com
Thanks.
Scott Langley
106th Congress Simulation
This simulation operates on the assumption that if the same legislation that appeared in the 105th Congress appeared in the 106th, then the members of the two parties would vote in same percentages - for, against, present, or not voting - as they did previously. Thus, if 70% of the members of a party voted yes on a certain roll call vote in the 105th Congress, then 70% of the members of that party in the new 106th Congress would vote that way. The vote to pick the Speaker of the House in 1997 cannot be broken down this way so it is not included. Given new party totals for the 106th Congress, you should be able to easily predict the results of this vote on your own.
In the 105th Congress, there were ### roll call votes in the House and ### roll call votes in the Senate. Of those votes, ### in the House and ### in the Senate had the parties splitting their votes in such a way that the outcome may have been different if the parties were represented in different numbers.
For a predicted 106th Congress consisting of:
House
Senate
There are ### changed outcomes of Senate votes and ### changed outcomes of House votes.
Copyright 1998