Confused or competent? How voters use the STV ballot paper

STV is often extolled because it allows voters to express a nuanced choice, but is criticised for being too confusing. In practice the system is little used, but evidence from where it is indicates much depends on how voters choose to use it. STV was used for the first time in Scottish local elections in 2007, providing valuable new evidence on how voters respond to the system. We use survey data to examine the incidence of various indicators of apparent failure by Scottish voters to exploit STV, and compare both the levels and patterns of incidence with equivalent data for Ireland. We find little sign of confusion in either country, but significant evidence of ballot order effects in Scotland.