Here is some analysis I did on surveys (specifically UP)
You can see how the 3 major TV surveys performed w.r.t UP in 2012. The reason I posted UP is because as we all know it is a psephologists nightmare. It is quite easy to predict RJ or MP or GJ or for that matter any 2 way fight. I am doing this to see which polling agency does a good job at capturing trends in a 3 or 4 way fight. My next post will be on the recent Delhi elections. But for now look at UP (please focus on vote share, seat projection is a disaster in most cases barring CSDS).
As you can see very well that C-voter collapsed, they just could not even catch the trend of SP doing better than the BSP. That is quite horrible for an election that delivered an astounding result. CSDS overshot the SP figure, but did a good job at capturing the trends, predicting BJP and cong vote share very well. They also got the seats almost on dot. Nielsen over predicted BJP/cong, and underestimated BSP/SP, but they got the gap between SP and BSP right.
But what is most interesting is that the average of the 3 surveys yields pretty good correlation with the actual results. But I would still applaud csds for getting the trends correct. They predicted national parties getting decimated, SP being an outright winner, so they broadly they tend to get the pulse, but overestimate a wave.
So applying the same lesson to this UP LS 2014, I see the same issue. CSDS is broadly getting the trend right as are other surveys that BJP is romping home. But i think they are overestimating the magnitude of the wave, my guess is the vote share of BJP will be close to 33% and the rest also on lines similar what the poll of polls shows. As far as seats go, I guess they will very close to what nielsen is showing in terms of seats. The poll of polls vote share is quite close to their vote share, so we can use their seat tally.
One more data point that supports this inference is the latest ibtl survey where BJP got 34.5% and 41 seats. So at 33% BJP gets 35 seats and at a 1.5% increment in the IBTL survey it gets 6 seats more which is usually the norm for BJP in UP.
So i would say as of jan/feb BJP -33%, BSP - 22%, SP-19%, Cong -12% is a reasonable number in UP. If BJP can grab an additional 3-5% vote in the coming months, they can hit 50 seats.