While everybody is digesting the results from Iowa and guessing how it might impact next Tuesday’s vote in New Hampshire, it is a good time to take a brief look over at elections in Europe — specifically the Republic of Ireland which will vote this Saturday.  What makes Ireland different is that it is one of a handful of countries that use the Single Transferable Vote.

The Single Transferable Vote system is a hybrid of proportional representation and preferential/ranked-choice voting.  Currently, the Democratic Party uses proportional representation to allocate delegates to presidential candidates.  As an initial caveat, both proportional representation and single transferrable vote require multi-member districts.  For the Democratic Party, delegates are allocated in multi-member districts — on both a state-wide and congressional district basis. (Typically, the congressional districts have between four and ten delegates.  State-wide delegates range from a low of two party leader delegates in Wyoming to ninety at-large delegates in California.)  For Ireland, the members of its parliament are elected in thirty-nine constituencies with the constituencies electing between three and five members to parliament.

There are three basic questions that a proportional representation system has to answer. First, how to decide fractional members?  In any system, after all the votes are counted, there is a set number of votes that exactly equals a certain number of delegates/members of parliament.  But, the odds that all of the candidates/parties will end up getting exactly the right number of votes is very, very slim.  Instead, it is likely that some candidates/parties will be  100 or 1,000 votes show of the number needed to win the next delegate/seat, and that other parties will have 100 or 1,000 votes more than the number need to win the previous delegate/seat.  This process is easy when you have two parties/candidates, you simply round up any fraction over .5 and round down any fraction under .5.  But when you have multiple parties, rounding may give you too many or too few seats.   Thus, a system using proportional representation needs to have a system for deciding which parties/candidates get the leftover delegates/seats once you are down to fractional seats. Continue Reading...