Conceptualising and measuring ‘centrism’ correctly on the Left–Right scale (RILE) - without systematic bias. A general response by MARPOR

The purpose of this response is to point out that claims of undue centrism in the MARPOR data are directly contradicted by its use to correct centrism in other leading policy measures including expert surveys. Secondly it demonstrates that there are grave problems with the logorithmic Left–Right scale proposed by Benoit and his colleagues (2011–12). Thirdly we reassert that MARPOR’s measurement formulation of Left–Right party positions is a proper one, on both conceptual and technical grounds.