In 2015, who will control the Senate? Warring models point in opposite directions. The NYT’s “The Upshot” looks at polls and other factors, and has Democrats favored. The Monkey Cage favors the Republicans. Who’s right?
For now, here’s the snapshot (following my past methods): in an election today, Democrats would retain control of the Senate with about 67% probability. Think of the Senate in 2014 as Schroedinger’s Cat: in that closed box, it’s currently 1/3 dead*. That will change over time. We open the box on November 4th.
See my further thoughts on the issue over at Politico. Here it is: The War Of The Senate Models.
Update: As per usual, here is the MATLAB code. It’s basically like the Presidential race, except that each state gets one “electoral vote,” i.e. one Senate seat. Super-simple. The basic algorithm is in senate2014_est.m. Then, senate2014_biascalc.m calls the basic algorithm, and allows you to see what would happen if polls moved over a range of possibilities. A simpler way is to simply set “bias=-2“, which moves margins toward the GOP by 2%, then run senate2014_est.m. Set bias to whatever your hopes and biases are. Mine is bias=0, which has a good track record on Election Eve.
Update #2: To learn about Schroedinger’s Cat and why I invoked it, click the image!
*”Dead”=GOP control, “live”=Democratic control. Some might see it the other way around…