How proportional representation will affect parties’ control over their MLAs has been a significant issue in the BC referendum on electoral reform. Opponents of proportional representation have suggested that that proportional systems increase the extent to which MLAs are beholden to parties. Proponents argue that proportional systems may have the opposite effect, increasing the ability of voters to get rid of MLAs that they may not like but whom a party might. The extent to which proportional systems strengthen or weaken party discipline depends on the system’s design. Closed list mixed member proportional systems will lead to higher levels of party discipline, dual member proportional systems will likely not change the level of party discipline, and open list mixed member proportional and rural urban proportional systems will weaken party discipline.
There are two mechanisms through which electoral systems can affect party discipline. First, electoral systems can affect how much control parties have over which candidates are likely to get elected. The more parties determine who is most competitive from their party, the more disciplined parties will be. In such cases MLAs that toe the party line are likely to be rewarded with a higher likelihood of re-election. MLAs that break with the party leadership can be punished with a lower likelihood of re-election. Second, electoral systems affect the ability of voters to choose between candidates in the same party. When voters have a choice between multiple candidates from the same party they can punish candidates they do not think are responsive enough to their interests without having to defect to a party they dislike. This gives MLAs more of an incentive to represent their constituents even if doing so leads them to break with the party leadership from time to time.
First past the post offers some, but limited, ability for MLAs to resist party discipline on the first mechanism, and no incentive to resist party discipline on the second. Under first past the post, parties’ candidates in particular constituencies are chosen by local party members in the riding. At this stage, parties are limited in their ability to decide who runs for office and, in particular, who runs in competitive ridings. This being said, there are ways in which parties can exert significant control over who wins nominations. Parties vet candidates and can decline to allow candidates with problematic pasts or viewpoints that party opposes to run for the nomination in a particular riding. Party leaders can also refuse to sign the nomination papers of candidates that break with the party on too many issues. Regardless of the electoral system, parties have relatively broad leeway to remove MLAs who break with the party too much from the party caucus (these MLAs remain in the legislature, but as independents). Under first past the post parties relinquish some control over candidate choice to local party membership, but retain an ability to veto candidates leadership does not like.
On the second mechanism, first past the post offers very little to voters looking to punish MLAs for being too responsive to party discipline. Because only one candidate runs for any given party in any riding, voters cannot vote against an MLA from the party they prefer without also having to change the party they support. Under first past the post if you like a particular party but do not like their candidate you are out of luck. You either have to vote against the party you like to get a local candidate you prefer or for a local candidate you dislike to get the party you prefer.
Dual member proportional does little to change the incentives that MLAs face. Under this system individual candidates would still run in ridings, though most ridings would have two candidates from each party. Parties would choose a primary and secondary candidate for each riding, likely using processes that are very similar to the ones used under first past the post. They would likely retain the ability to vet candidates and to refuse candidates that do not fit with the party leadership’s beliefs. Voters would not be able to rank different candidates from the same party against each other. They would have to accept whichever candidate is listed as the primary candidate. As a result, voters would still face a difficult decision if their preferred party nominated a candidate they do not like as their primary candidate.
Mixed member proportional (MMP) could see some change in the level of party discipline in the legislature, though whether party discipline would increase or decrease depends on the design of the system. MMP compensates parties that receive fewer seats than their share of the vote by giving them extra MLAs off of a party list. The higher up a candidate is on the party list, the greater the chance they have of being elected. If parties decide on the order of the list, as is the case in closed list systems, list MLAs have a strong incentive to toe the party line. This is because parties are likely to reward well-disciplined MLAs with high positions on the party list and punish candidates that break with the party with low positions on the party list.
MMP systems can also be designed in a way that allows voters to determine the order of the party list. These types of systems are referred to as open list systems. In these systems voters cast an additional vote for a candidate on their preferred party’s list. The more votes a candidate gets, the higher they end up on the list and the more likely they are to get one of the extra seats the party needs to be proportionally represented. Where closed list MMP systems give MLAs a strong incentive to fall in line with their parties, open list systems give them an incentive to break with their party if doing so will lead voters to push them higher up the party list. For example, an MLA who breaks with their party to support an issue important to women may win over large numbers of feminist voters in the party, and as a result end up higher up on the party’s list.
Additionally, open list MMP allows voters an opportunity to vote against candidates they dislike without defecting from their preferred party. If one does not like a candidate on the party list one can simply vote for someone else on the list. If a disliked MLA does not get enough votes from their parties’ supporters they fall to the bottom of the party’s list and have a lower likelihood of being elected. This gives MLAs another incentive to be responsive to their party’s voters even if doing so leads them to break with party leadership at times. This is only the case, however, for MLAs elected off party lists. MLAs elected in ridings would face the same incentives and party discipline that MLAs face under first past the post.
John Horgan has indicated a strong preference for open list systems making it likely that this type of system will be used if voters vote for MMP. The referendum question and Elections BC information on the options on the ballot do not commit the government to either an open or closed list system.
Rural urban proportional systems offer the greatest opportunity for voters to reward MLAs that push back against party discipline. Under this system rural parts of the province would use MMP, and as a result, rural MLAs would face the same incentives discussed above. Urban areas, however, would use a single transferable vote (STV) system that allows voters to rank order candidates from different parties against each other. This weakens party discipline through two mechanisms. First, by rank ordering candidates from the same party, voters would exert control over which candidate from a party stands the best chance of getting elected. The more first place votes a candidate receives, the more likely they are to win election regardless of what the party leadership thinks of them. As a result, MLAs would have an incentive to break with their party if doing so means getting more first place votes.
STV systems also allow voters to rank candidates from different parties. This gives voters a great deal of control over how they weigh the pros and cons of voting for candidates they like from parties they dislike and candidates they dislike from parties they like. A voter who dislikes a candidate from their preferred party may choose to rank all of the candidates from their preferred party above the disliked candidate. The voter, if they choose, could go further and start ranking candidates from less preferred parties above their disliked candidate. This is something that the voter would not be able to do under an open list MMP system. This gives MLAs strong incentives to be responsive to voters, even if it means breaking with party discipline. Voters have plenty of other options to choose from should an MLA disregard their interests in order to toe the party line.
It is important not to overstate the influence that electoral systems have over party discipline. Parties control a significant number of MLAs’ opportunities for career advancement. Control over cabinet and committee appointments, speaking time, and the ability to vet who runs for a party offer party leadership a number of levers through which to punish MLAs that break with party discipline regardless of the electoral system. None of this would change under a different electoral system. At the same time, by influencing which MLAs are more likely to be elected, electoral systems will affect party discipline. Closed-list MMP systems will likely have the strongest levels of party discipline, followed by both first past the post and dual member proportional systems. Open list MMP systems will likely have lower levels of party discipline than first past the post systems and rural urban proportional systems will likely have the lowest level of party discipline of all of the systems on offer in the BC referendum.