A new Researcher Contribution is available for download from the Data Center. The contribution was prepared by Russell J. Dalton and is titled “Party System Polarization Index for CSES Modules 1-4”. by Adrian Lauf | Apr 27, 2017 | Uncategorized A new Researcher Contribution is available for download from the Data Center. The contribution was prepared by Russell J. Dalton and is titled “Party System Polarization Index for CSES Modules 1-4”.