Pickup Projection Trend - Poll Based Model

Updated 18 October 2010

Political Junkie Too, the resident statistical wiz at Freerepublic.com has taken the average KeyHouseRaces ratings by our 6 "Experts" for each of the districts on our Master List and built a computer model to generate an estimate of the outcome of the 2010 election for the House of Representatives. The model uses a technique known as a Monte Carlo simulation that utilizes probability functions for each of the KeyHouseRaces ratings categories - Leans D, Toss Up, etc and then runs a simulated election based on these probabilities.

As we started to get some decent poll data PJ Too decided to build a second model that utilized poll data less than 60 days old and, for districts where we had no poll data, to utilize the basic "Expert Rating" version of the simulation. The chart and the plot below show the calendarized results of this "hybrid" poll and expert-based simulation of the November election.

The results shown below are the average of 32,000 runs of the hybrid computer model each week since July 31st. Since the polls tend to lead the "Experts" it is not surprising that the poll-based simulation predicts a larger number of GOP seats than the Experts based model. This is simply due to the fact that Republican prospects have been improving weekly and the expert ratings updates tend to lag the polling data.

You can see the original Political Junkie Too Expert Base simulation results HERE.

 

Poll Based Model
Week House Seat Projection Probability of

GOP Control		 Projected GOP Pickup
GOP Dem
31-Jul-10 212 223 8.43% 33
7-Aug-10 211 224 4.51% 32
14-Aug-10 211 224 4.44% 32
21-Aug-10 213 222 11.83% 34
28-Aug-10 217 218 42.58% 38
4-Sep-10 218 217 50.40% 39
11-Sep-10 219 216 66.39% 40
18-Sep-10 219 216 62.30% 40
25-Sep-10 218 217 61.17% 39
2-Oct-10 221 214 83.86% 42
9-Oct-10 223 212 96.15% 44
16-Oct-10 226 209 99.33% 47
23-Oct-10 228 207 99.94% 49
30-Oct-10 231 204 99.94% 52
1-Nov-10 233 202 99.94% 54



 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Poll Based Model

The three figures below show:

  • A plot of the data from the above table
  • An animated GIF showing the GOP and Dem leaning seats from the KHR Master List from 10 July to the current date
  • An animated GIF showing the GOP and Dem leaning seats for all House seats from 10 July to the current date

The data from the above table is plotted below.

The Dashed Red Line shows the probability that the GOP will re-take the House and it crossed over the 50% point on September 11th.

The Dark Black Line shows the trendline for House GOP seats that has steadily risen since early August.

That Purple Line at the top of the plot represents an estimate of the maximum number of seats that the GOP could pickup. Only 10% of the Monte Runs exceeded these value.

Likewise, the Green Line provides an estimate of the lower limit of the GOP seats - only 10% of the Monte Carlo runs fell below these values.

The bottom line: The trend is up and we need to keep it going up right to November 2nd.

Animated GIF - KHR GOP & Dem Leaning Seats Only  - July 10 to Current Date

Animated GIF - All GOP & Dem Leaning or Safe Seats  - July 10 to Current Date