The aim of the project was to develop new explanatory models for party choice. The consideration set model presumes that voters decide their party choice in stages. The most intuitive version of the choice set models is that voters first single out preferred parties that they consider voting for. In a second stage, the final decision is being made. Consideration set models in electoral research is inspired from psychology, marketing research and consumer behavior research. In this project, we apply these models of human decision making on voters decision processes at elections.

During the “Super election year 2014” – with European Parliamentary elections in May and General elections in September – a large seven wave data collection was initiated by the Swedish National Election Studies program. A large random sample was invited to participate in a webbased survey – the SNES Internet Campaign Panel study 2014. The CSM panel was specifically designed for this project and was the main data source for analyses carried out in the projects’ publications. Theory development of CSM-models was manifested by a large number of unique survey instruments that were developed in order to test underlying assumptions of the CSM model.
The project was engaged in international networking and collaboration with researchers sharing the interest of developing consideration set models of voting behavior. We invited scholars to a panel in ECPR in Montreal in august 2014. Participants decided to suggest a symposium – a collection of articles – to one of the leading journals of the field – Journal of Electoral Studies. The special symposium of CSM was finally published in september 2018 with Henrik Oscarsson and Martin Rosema as editors.

The findings from the CSM project take the form of a) a developed theoretical model of voters’ decision making, b) suggestions of how to best measure voters’ considered alternatives and estimate choice set models in electoral research and c) a large number of empirical contributions aiming to evaluate the performance of the model. The choice process of voters as presented in the CSM research is based on very general principles about human decision making. When people choose from a set of alternatives, they can do this in two ways. One possibility is to immediately select the chosen alternative from the whole set of available options. For example, an individual could make an inventory of the positive and negative characteristics of all alternatives and then select the one with the best overall score. Another possibility is to decide in stages. The simplest form would be a decision in two stages, in which the set of available alternatives is first limited to a smaller number of viable options, while in the next stage the final choice is made within that set. Such a sub-set of viable options has been referred to as consideration set.

The model involves a hierarchy of nested sets from which the choice results. The starting point is the universal set of choice options, which comprises all available options. The alternatives that a person knows constitute the awareness set, which thus is a sub-set of the universal set. The selection of viable alternatives leads to the formation of the consideration set out of the awareness set, which in turn is further limited to the choice set. Out of this set the ultimate choice is made and the behaviour results. Our suggestions as regards research design, measurement, and statistical modelling are: the use of pre-election panel surveys, direct measures of electoral consideration sets, and statistical models suitable for analysing dichotomous variables and voter-party dyads.

The empirical contributions demonstrate that CSM produce new insights about individual decision making, party competition, and particular electoral behavior such as party leader effects and strategic voting.

The basics of the CSM – that voters form a consideration set and then proceed into a final stage of decision making – has been communicated to a large audience of students, parties, interest organisations, scientific community and the general public, reported in books, conference papers, chapters in books, journal articles, interviews, and talks (f c at the EUI in Budapest and the ANU in Canberra). Data is deposited at the Swedish National Data archive (www.snd.gu.se) which allow for secondary analyses in the future.
One key scientific principle is that theoretical models should not be tested on the same data that was used in their development. New contexts and new empirical observations that are independently collected should be used. As a consequence of the project, many of the survey instruments developed in the project are already being used in subsequent data collections within the SNES program, f c the 2018 election studies in Sweden. This will be an opportunity to test if the CSM model can successfully be applied to explain voting behavior in the 2018 election. The likely spin off of the CSM project is several international publications in the future.

Data from the CSM panel was deposited at the national data archive (SND) in September 2018. It is available for secondary analyses by students and researchers interested in CSM.