PP: 21 PNM: 20
Close race between Partnership, PNM
Poll results and seat projectionWith just weeks remaining until the September 7 general election, the SBS poll and seat projection anticipates a close race between the People's National Movement (PNM) and the People's Partnership (PP).
The model suggests there is a 93% chance that the final result will be 21-20, with Tunapuna being the closest seat. In the poll, the PP has a better chance of winning Tunapuna at the current time. Other seats such as St. Joseph, La Horquetta/Talparo, or Lopinot/Bon Air West are also projected to be won by close margins.
MethodologyThe Poll: SBS interviewed 1,412 adults in Trinidad and Tobago via live telephone calls from July 6th to July 22nd. The respondents were sampled from households of registered voters in the 257 polling divisions in Trinidad and Tobago, whose election results best predict the national election results in past elections between 2000 and 2010. There are a total of 1,547 polling divisions in Trinidad and Tobago. The margin of error of the poll is +/- 3%. The poll was commissioned by the Express Newspapers.
The Modeling/Simulation: SBS grouped all polling divisions into seven clusters, using the kmeans algorithm. Each cluster exhibited similar patterns in election results (or “electoral swings”) in the five general elections since 2000. Using the poll, SBS then estimated the current swing, or change in political support, within each cluster of polling divisions and therefore the estimated level of support for each party in every polling division. Respondents would claimed to be undecided were modelled as having the average partisanship of their polling division. To quantify the uncertainty in the projection, SBS ran 10,000 simulations using a technique called bootstrapping which repeatedly samples the sample of 1,412 interviews to determine how sensitive a result is to in-sample variance.
Poll results and seat projectionThe 2015 general election race between the PNM and the People's Partnership could not be closer. The SBS poll model and electoral seat projection says that just one seat is likely to separate the two on September 7.
The general shape of the poll results follows a similar pattern to the last SBS poll: The favourability of the Prime Minister continues to outstrip that of the Leader of the Opposition, and the rate of undecided voters remains over 30%. These results will be detailed further in Part II of this report.
The ILP's appeal has reduced to below 3%. They are unlikely to even re-elect a candidate in Chaguanas West. Other parties combined for 3%.
Using the simulation outlined in the methodology, SBS anticipates that the constituencies of Tunapuna, La Horquetta/Talparo, and Lopinot/Bon Air West, are most likely to be the closest, and that Tunapuna is likely to make the difference. The model suggests that up to 6 seats may be a margin of less than 1,000 votes.
The larger sample size of the poll, and the further assumption that “undecided” voters may vote according to historical patterns at the polling division-level significantly reduced the uncertainty in the model compared to the last Express poll.
Path to 21 seatsOf the 10,000 simulations run, only 2 (0.02%) presented the possibility of a party winning without Tunpauna. Only 7% of the runs featured one party winning more than 21 seats. In almost all of these cases – in a case where the PNM wins Moruga/Tableland or the People's Partnership wins Lopinot/Bon Air West – that party also wins Tunapuna.
About Solution by SimulationSolution by Simulation Limited (SBS) is a data analysis firm which uses computer modelling to probe and provide insight into human behaviour. SBS provides market research and data analysis services for a number of commercial, academic, and civil society clients. SBS was founded by Nigel AR Henry, BS (Yale) MA (GWU), following Mr. Henry's service as the lead numerical analyst for the Southeast US for Obama for America campaign. SBS debuted in Trinidad and Tobago producing the only published poll to forecast the 12-0 victory of the PNM in the 2013 THA Elections. Over five elections in 2013 and 2014, Solution by Simulation has proven to be consistently accurate in its pre-election polling.
http://trinidadexpress.com/20150801/news/pp-21-pnm-20