Methodology and sources

Poll of Polls is a weighted aggregation of polls from Sifo, Demoskop, Novus, and Ipsos. Statistics Sweden's large-scale Political Party Preference Survey from May and November (SCB/PSU) is part of Poll of Polls as well. These surveys all pose similar questions (if the election was held today, which party would you vote for?).

The method behind Poll of Polls is based on a moving average of the results (in percent) that the parties get in the polls. A simple function (Ipoly) is used to give more weight to recent polls. The results are also weighed to favor polls with a large number of respondents. The function sensitivity, i.e. the degree to which new polls affect the results, is tuned to not give too much weight to surprising results in a single survey.

The collaboration between Datastory and the Swedish National Election Studies Program was made possible with funding from Riksbankens Jubileumsfond.