Proportional Seat Distribution
How does PSD Work?
The Basics
This section looks at how Proportional Seat Distribution (PSD) turns votes into proportional representation. If you want, once you have a solid foundation for the general way PSD works, you can take a look at the technical details.
The Voters
Voting with PSD involves the simple mark-an-X ballot. On election day, voters go to their polling station and receive their ballot. The ballot has the names of all candidates and identifies each candidate's affiliated party, if any. It is up to the voter to check off the box of their choice. Simple!
PSD lends itself easily to a wide variety of accessibility measures including audio/telephone voting, mail-in voting, advanced polls, electronic ballot counting, and even internet voting, if desired.
As polls close and ballots get counted, preliminary results are sent to election headquarters. If incoming results are to be made public in real time, the popular vote results can be broadcast and updated as data arrives. Since results for specific electoral districts are highly dependent on the popular vote and the exact vote count for each candidate, all polling results must be in before representatives can be declared.
Calculating Results
After receiving the results from all the polling stations, the first step is to determine whether any independent candidates received more votes than anyone else in their riding. If so, the independent candidate represents the riding. Each party's total vote count is then used to divide the remaining seats between them so that any party underrepresentation (and overrepresentation) is minimized. This directly ensures that party representation is proportional to their popular support.
After the number of seats for each party has been determined, each of the ridings not represented by an independent candidate is paired up with the most suitable party candidate. This is done by measuring the success of each party candidate's performance in their riding and then ranking them accordingly. The highest ranked party candidate is paired up with her riding: she represents the riding while the other candidates in the riding are removed from the ranked candidate list, the amount of seats remaining to be given to her party goes down by one, and then the process is repeated until all seats have been distributed and all districts have a representative. In this way, each party's most successful candidates get a seat and the party with the best success in a given riding represents the riding.
Whether applied together to all regions to maximize overall proportionality or separately to constituent regions to maximize proportionality in each region, the entire calculation process is completed in seconds. The results are then released, along with the success ratings and candidate ranking data for ease of verification.